JPH06238914A - Suction operation controlling method of ink-jet recording device and ink-jet recording device - Google Patents

Abstract

PURPOSE:To constitute a method and device so that lowering of throughput is controlled to the minimum while keeping a recording head at the optimum state, by a method wherein ink within a recording head is sucked at timing to be decided based on the number of discharge dots, time left standing and temperature of the recording head. CONSTITUTION:An ink-jet recording device is provided with a time count device 24 to count a standing time of an ink jet recording device since power is turned on to the ink-jet device for the first time. A quantity of electricity corresponding to a counted value by the time count device 24 is applied to a suction operation control device 23 and in the suction operation control device 23, suction operation instruction are sent to a record control device 22 and suction device 12 based on an input value from the time count device 24, an input value from a dot count device 25 and an input value from a temperature sensor 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling the suction operation of an ink jet recording apparatus and an ink jet recording apparatus for sucking ink in the recording head to remove air bubbles in the recording head.

[0002]

2. Description of the Related Art In an ink jet recording apparatus for recording by a recording head which ejects ink as a recording liquid, bubbles are gradually generated in a nozzle or a fitting portion during recording or in a state of being left unrecorded. Normal recording may not be possible due to possible (non-ejection) or ink drop. Therefore, in order to remove the bubbles, the conventional ink jet recording apparatus includes a cap for capping the recording head and a head recovery device having a suction pump for sucking the inside of the cap, and capping is performed at a position where the cap and the recording head face each other. After that, the suction pump is used to suck the bubbles in the recording head. This suction is an important technique for improving the reliability of the inkjet recording device.

Even if the suction condition for achieving the optimum bubble removal performance is determined, since the volume of the bubble varies in different suction operation timings, the same bubble removal capability is always exhibited. is not. Therefore, in the conventional ink jet recording apparatus, in order to maintain a good bubble removal capability, the dot count or the leaving time is counted, or the dot count and the leaving time are set so that the suction is performed in a state where the bubble volume is as constant as possible. Both time counts were performed and the suction operation was controlled according to these count values. Specifically, based on the earlier of the time point when a predetermined time has passed from the initial time point and the time point when a predetermined amount of recording has been completed from the initial time point,
The suction operation timing of the recording head has been decided.

[0004]

However, in the above-mentioned conventional control of the suction operation, (1) the difference in the amount of recording bubbles caused by the difference in the recording duty level when recording the same number of dots is not taken into consideration. (2) The amount of residual bubbles generated after the recording is not taken into consideration. (3) The difference in the amount of left bubbles generated depending on the environmental temperature is not taken into consideration. For this reason, depending on the temperature of the print head, unnecessary suction operation is performed and the throughput of the printing apparatus is reduced. At the same time, the amount of waste ink is increased, and conversely, ejection failure due to bubbles occurs before the suction operation. There was a problem that it may cause.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suction operation control method for an ink jet recording apparatus and an ink jet recording apparatus in which the deterioration of the throughput can be suppressed to a minimum while maintaining the recording head in an optimum state.

[0006]

In order to achieve the above object, the suction operation control method for an ink jet recording apparatus according to the present invention, in order to remove air bubbles generated in a recording head for recording by ejecting ink, In the suction operation control method for an inkjet recording apparatus, which sucks ink in the recording head at a predetermined timing, the predetermined timing is the number of dots ejected from the recording head,
It is characterized in that it is determined based on the leaving time of the recording head and the temperature of the recording head.

Further, as the predetermined timing, the number of dots ejected from the recording head and the leaving time of the recording head when the defective ejection due to the bubbles occurs with respect to the temperatures of various recording heads are obtained in advance. During recording, while detecting the temperature of the recording head, the number of ejection dots exceeds the number of ejection dots obtained for the detected temperature, or the leaving time is for the detected temperature. The timing may be the earlier of the required leaving time or the earlier of the two.

Further, the amount of ink suctioned in the recording head is changed according to the number of dots ejected from the recording head, the leaving time of the recording head, and the temperature of the recording head. The interval of the suction operation for sucking the ink inside may be shortened as the use time of the recording head increases.

The recording head may be provided with an electrothermal converter for generating thermal energy for ejecting ink, in which case the recording head is applied by the electrothermal converter. Thermal energy
The film may be ejected from the ejection port by utilizing the film boiling generated in the ink.

The ink jet recording apparatus of the present invention comprises a recording head for recording by ejecting ink, and a suction means for sucking the ink in the recording head in order to remove bubbles generated in the recording head. In an ink jet recording apparatus having the above, a dot counting means for counting the number of dots ejected from the recording head, a time counting means for counting the leaving time of the recording head, a temperature detecting means for detecting the temperature of the recording head, and Suction operation control for sending a suction operation command to the suction means based on the number of ejection dots counted by the dot counting means, the leaving time counted by the time counting means, and the temperature detected by the temperature detecting means And means.

Further, the suction operation control means is such that the number of ejection dots counted by the dot counting means is
At a time point when the number of ejection dots exceeds the number of ejection dots at the time of ejection failure due to the air bubbles with respect to the temperature of the recording head detected in advance by the temperature detection unit, or
Any one of a time point at which the leaving time counted by the time counting means exceeds a leaving time when a defective ejection due to the bubbles occurs with respect to the temperature of the recording head detected by the temperature detecting means, which is obtained in advance. A suction operation command may be sent to the suction means at an earlier point.

Further, the suction operation control means is responsive to the number of ejection dots counted by the dot counting means, the leaving time counted by the time counting means, and the temperature detected by the temperature detecting means. , For changing the amount of suction of the ink in the recording head by the suction means, or shortening the time interval of sending a suction operation command to the suction means in accordance with the increase in the use time of the recording head. It may be controlled to.

Further, the recording head may be provided with an electrothermal converter for generating thermal energy for ejecting ink, in which case the recording head is applied by the electrothermal converter. Thermal energy
The film may be ejected from the ejection port by utilizing the film boiling generated in the ink.

[0014]

FIG. 8 is a graph showing the relationship between the number N of recorded dots and the bubble volume. The bubble volume tends to increase as the number N of recording dots increases. Also, this rate of increase changes with temperature. That is, when the temperature of the recording head is A, ejection failure occurs due to an increase in bubble volume when N ₁ dots are recorded from the start of recording, but when the temperature of the recording head is B (B> A), it is more than N ₁ . Small number of recording dots N ₂
Therefore, ejection failure occurs due to an increase in bubble volume.

FIG. 9 is a graph showing the relationship between the standing time t and the bubble volume. Here, the leaving time t means the passage of time after the recording apparatus is first operated regardless of whether or not the recording head performs recording. The bubble volume tends to increase as the standing time increases. Also, this rate of increase changes with temperature. That is, when the temperature of the recording head is A, ejection failure occurs due to an increase in bubble volume when left for a time of t ₁ , but when the temperature of the recording head is B (B> A), it is shorter than t _1. Discharging failure occurs due to an increase in bubble volume at the standing time t ₂ .

From these facts, it is possible to accurately estimate the amount of bubbles generated by considering the temperature of the recording head, and it is possible to accurately prevent ejection failure.

Therefore, in the suction operation control method of the ink jet recording apparatus of the present invention, the timing of sucking the ink in the recording head for removing the bubbles in the recording head is set as follows.
Since it is determined based on the number of dots ejected from the recording head, the recording head leaving time, and the temperature of the recording head, it is possible to accurately estimate the amount of bubbles generated in the recording head according to the temperature of the recording head. Therefore, it is possible to always determine the suction timing at which the same bubble removing ability can be exhibited. as a result,
Only a minimum number of suction operations are required, and the throughput of the printing apparatus can be minimized while keeping the print head in an optimal state.

[0018]

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

(First Embodiment) FIG. 1 is a schematic perspective view showing the structure of an embodiment of the ink jet recording apparatus of the present invention. As shown in FIG. 1, the carriage 2 has a pin (not shown) that engages with the spiral groove 5a of the lead screw 5, and the forward / reverse rotation of the drive motor 11 is controlled by the two drive force transmission gears 9, 10.
By being transmitted to the lead screw 5 via the carriage 2, the carriage 2 is reciprocated in the directions indicated by arrows a and b.
The carriage 2 is equipped with an ink jet cartridge 1 in which an ink tank (not shown) that contains recording ink and a recording head (not shown) that ejects ink toward the recording paper 30 are integrated. A platen 4 for transporting the recording paper 30 is rotatably provided facing the inkjet cartridge 1. The recording paper 30 conveyed by the platen 4 is pressed against the platen 4 by the paper pressing plate 3 on the side facing the inkjet cartridge 1, and is held so that the interval between the recording paper 30 and the inkjet cartridge 1 becomes a predetermined interval. Then, the recording operation of ejecting ink from the recording head while moving the carriage 2 by the drive motor 11 is performed by the recording control unit 2.
The number of recorded dots at that time is counted by the dot counting means 25.
Further, the recording head of the inkjet cartridge 1 has a temperature sensor 21 for measuring the temperature of the recording head.
Is attached, and the amount of electricity corresponding to the value is output to the suction operation control means 23 that controls the suction operation described later. The temperature sensor 21 does not necessarily have to be attached to the recording head, and can be attached to any position of the inkjet recording apparatus as long as the temperature of the recording head can be predicted.

Two photocouplers 7 and 8 are provided on the left end side in the drawing of the carriage 2 in the moving direction. Each of these photocouplers 7 and 8 is a home position detecting means for confirming the existence of the lever 6 provided at the left end portion of the carriage 2 in the figure in this area and switching the rotational direction of the drive motor 11 or the like. .

A cap member 13 supported by a cap support member 14 is provided at a position outside the range of reciprocating motion of the ink jet cartridge 1 during the recording operation and at which the ink jet cartridge 1 is moved during the suction operation. There is. The cap member 13 caps the front surface (ejection port surface) of the recording head of the ink jet cartridge 1. In this state, the suction means 12 sucks the inside of the cap member 13 to increase the viscosity of ink and bubbles in the recording head. A head recovery operation such as removal of is performed. The blade support member 1 is provided on the side of the cap member 13.
A cleaning blade 15 supported by 6 is provided. The cleaning blade 15 is the blade supporting member 1
6, the ink jet cartridge 1 is supported so as to project toward the ink jet cartridge 1 and can come into contact with the front surface of the recording head. As a result, after the suction operation, the cleaning blade 15 is projected into the movement path of the inkjet cartridge 1, and the dirt and the like on the front surface of the recording head is wiped off as the inkjet cartridge 1 moves. Needless to say, the cleaning blade 15 is not limited to this form, and a known cleaning blade can be applied.

Further, the ink jet recording apparatus of this embodiment is provided with a time counting means 24 for counting the time that the ink jet recording apparatus is left unattended since the ink jet recording apparatus was first turned on. The amount of electricity according to the value counted by the time counting means 24 is output to the suction operation control means 23, and in the suction operation control means 23, the input value from the time counting means 24, the input value from the dot counting means 25, and Based on the input value from the temperature sensor 21, a suction operation command is sent to the recording control means 22 and the suction means 12.

Here, the recording head described above is shown in FIG.
Will be described with reference to. FIG. 2 is a perspective view of a main part of the recording head of the inkjet cartridge shown in FIG. As shown in FIG. 2, the print head has a plurality of discharge ports 1b formed at a predetermined pitch on a discharge port surface 1a facing a recording sheet 30 (see FIG. 1) at a predetermined interval, and is common. An electrothermal converter (e.g., a heating resistor) 1e for generating energy for ejecting ink is disposed along the wall surface of each liquid passage 1d that connects the liquid chamber 1c and each ejection port 1b.
The common liquid chamber 1c communicates with the ink tank of the inkjet cartridge 1 (see FIG. 1) described above, and ink is supplied from the ink tank to the common liquid chamber 1c. The ink that is supplied from the ink tank to the common liquid chamber 1c and temporarily stored in the common liquid chamber 1c is caused by the capillary phenomenon to cause the liquid passage 1
d into the liquid path 1 to form a meniscus at the discharge port 1b.
Keep the condition that d is satisfied. At this time, when the electrothermal converter 1e is energized via an electrode (not shown) to generate heat, the ink on the electrothermal converter 1e is rapidly heated to generate bubbles in the liquid passage 1d. The expansion causes the ink to be ejected from the ejection port 1b.

Here, the electrothermal converter 1e is shown as the energy generating element for generating energy, but the present invention is not limited to this, and a piezoelectric element for generating mechanical energy for instantaneously applying the discharge pressure may be used. .

Next, the suction operation control procedure of the ink jet recording apparatus of this embodiment will be described with reference to FIG.

First, for the first time, the ink jet recording apparatus is electrically charged.
When the source is turned on (S301), time counting means 2
The counting of the standing time t by 4 is started (S302),
After that, even if the inkjet recording device is turned off,
Continue to be undone. In addition, the graphs of FIG. 8 and FIG.
From the number of recorded dots and
Inkjet recording device is allowed to stand for various recording head temperatures.
It is calculated for each degree, and it is applied to various average print head temperatures S.
Suction dot counter value N that requires suction operation
_VAC(S) and suction leaving time counter value t_VAC(S)
In advance as a table as shown in FIG.
Ku.

After the power is turned on, the standing time t is compared with the suction standing time counter value t _VAC (S) (S303).
Here, if t> t _VAC (S), the suction operation control unit 23 sends a suction operation command to the recording control unit 22 and the suction unit 12.

Left time t and suction left time counter value t
_VACIn comparison with (S), t ≦ t_VACIn case of (S)
Initializes the recording dot counter value N (S304),
At the same time as the start of recording (S305), the dot counting means 25
To start counting the recording dot counter value N
(S306). At the same time attached to the recording head
One line of recording was performed by the temperature sensor 21 (S
307) and the recording head temperature T is measured (S30
8) Calculate the total temperature TT from the start of recording (S
309). In the case of the first record of the first line, the record head
The temperature T becomes the total temperature TT as it is. And
By dividing the total temperature TT by the number of recording lines G, the average
The temperature S is calculated (S310). Average recording head temperature S
When is calculated, refer to this value and
Input value N and suction dot counter value N_VACComparison with (S)
Is performed (S311). Where N> N_VAC(S)
If the suction operation is performed, the suction operation control unit 23 issues a suction operation command.
To the recording control means 22 and suction means 12
Unter value N and suction dot counter value N_VACRatio with (S)
By comparison N ≦ N_VACIf it becomes (S), then leave it unattended
Interval t and suction leaving time counter value t _VACCompare with (S)
Perform (S312). Where t> t_VACBecomes (S)
If the suction operation control means 23
It is sent to the recording control means 22 and the suction means 12. Other than that
If so, it is judged whether or not the recording is completed (S31).
3) If there is data to be recorded next, record control
Step 22 ends the recording. If data still exists
Data does not exist in the processing from S303 described above.
Repeat until it becomes.

On the other hand, when the suction operation command is sent, the recording control means 22 interrupts the recording, moves the recording head to a position facing the cap member 13 to prepare for the suction operation, and the suction means 12 causes the cap member 13 to move. Is driven to cap the ejection port surface of the recording head, and a suction operation is performed (S314). After the suction operation is completed, the values of the recording dot counter value N, the leaving time t, the total temperature TT, the number of recording lines G, and the average recording head temperature S are reset (S31).
5) Then, it is judged whether or not the recording is completed (S313). If there is data to be recorded next, the recording control means 22
Recording is started by, and recording is ended in other cases.

As described above, the number of suction operations for keeping the print head in an optimum state is required by setting the number of print dots required for the suction operation and the leaving time according to the temperature of the print head. With a minimum number of times, it is possible to minimize the decrease in the throughput of the inkjet recording apparatus while keeping the recording head in an optimum state.

In the present embodiment, an example is shown in which the suction operation is performed based on the comparison result of each counter value, but the invention is not limited to this, and the suction operation is always performed after the power is turned on, and the ink thickened or fixed while being left standing. May be removed.

(Second Embodiment) FIG. 5 is a flow chart of a second embodiment of the suction operation control method for an ink jet recording apparatus according to the present invention. The inkjet recording apparatus used in the present embodiment may have the same configuration as that shown in FIG. 1, and therefore the suction operation control procedure of the present embodiment will be described below with reference to FIGS. 1 and 5. To do.

First, when the ink jet recording apparatus is turned on for the first time (S701), the suction operation A is performed (S702). The suction amount at this time is 0.1 cc.
If the ink jet recording apparatus is not turned on for the first time, the temperature sensor 21 attached to the recording head is used.
The print head temperature T (° C) is measured with the suction parameter V
Is calculated (S703). The suction parameter V is expressed by V = T × (N × a + t × b) ... (1), where N is the recording dot counter value (emission) and t is the leaving time (minutes). Represents As the value of the recording dot counter value N, the final value when the inkjet recording apparatus was used last time is used. Further, a and b are dot counter coefficients and leaving time coefficients for aligning the digits of the recording dot counter value N and the leaving time t, respectively, so as to give weights uniformly. Here, the dot counter coefficient a = 1 and the leaving time. The coefficient b = 3.

When the suction parameter V is calculated, the suction operation B is performed (S704). The suction operation B is for turning on the power after the inkjet recording apparatus has been used once in the past.
It is the suction operation in the state. The suction amount in the suction operation B is determined according to the value of the suction parameter V by a predetermined table as shown in FIG. Thereby, the suction amount is small when the value of the suction parameter V is small, and the suction amount is large when the value of the suction parameter V is large. In FIG. 6, the value of the suction parameter V is 1000
The value of the suction parameter V is 10000 or less.
This is because the suction operation has already been performed when the ink jet recording apparatus was used last time, as will be described later.

When the suction operation A or the suction operation B is completed, the recording dot counter value N, the leaving time t, and the value of the suction parameter V are initialized (S705), and the counting of the leaving time t is started again (S706). Here, the leaving time t continues to be counted even when the ink jet recording apparatus is powered off.

Next, the suction parameter V is calculated again by the equation (1) (S707), and the suction parameter V obtained in S707 is compared with the set value V _VAC (S70).
8). Here, the value of the set value V _VAC is set to 10000, and when V> V _VAC , the suction operation command is sent from the suction operation control means 23 to the recording control means 22 and the suction means 12. C is performed (S715), and the values of the recording dot counter value N, the leaving time t, and the suction parameter V are initialized (S716). The suction amount in the suction operation C is 0.15 CC. When the value of the suction parameter V is 10000 or less, recording is started without performing the suction operation (S709).

Immediately after the recording is started, the recording dot counter value N is started to be counted (S710). During recording, every time one line is recorded (S711), the temperature sensor 2
The printhead temperature T is measured at 1 and the suction parameter V is calculated by the equation (1) (S712). And S712
The suction parameter V obtained in step _S1 is compared with the set value V _VAC (S713), and the value of the suction parameter V is set to the set value V _VAC.
Suction operation C when _VAC becomes larger than 10,000
(S715) to initialize the recording dot counter value N, the leaving time t, and the suction parameter V (S71).
6). When the value of the suction parameter V is 10000 or less, or when the above-described S716 is completed, it is judged whether or not the recording is completed (S714). If there is no data to be recorded next, the recording control means 22 terminates the recording.
If data still exists, the above-described processing from S707 is repeated until the data no longer exists.

As described above, the throughput during recording can be improved by always performing the suction operation in the preparatory stage before the start of recording so as to minimize the suction operation during recording. Further, by optimizing the suction amount in the suction operation according to the print head temperature T, the print dot counter value N, and the leaving time t, the ink consumption amount by the suction operation can be suppressed and the running cost can be reduced. it can.

The coefficients a and b, the set value V _VAC , and the suction amount used in this embodiment may be appropriately changed according to the type of the recording head and the operating environment.

(Third Embodiment) Generally, the recording head in an ink jet recording apparatus deteriorates as its usage time increases. Therefore, in the present embodiment, in the processing of the second embodiment shown in FIG. 5, after the processing of initializing the suction parameter V (S705, S716), counting processing of the suction operation number D is provided, respectively, and the suction parameter V In the calculation (S703, S707, S712), FIG.
The dot count coefficient a and the standing time coefficient corresponding to the suction operation number D determined by the table as shown in FIG. In this case, since the dot count coefficient a and the leaving time coefficient b are set to increase as the suction operation number D increases as shown in FIG. 7, the suction parameter V increases as the suction operation number D increases. The value of will also increase. Therefore, as the suction operation number D increases, the suction operation parameter V> the set value V _VAC
Is easily established, and the suction operation B shown in FIG.
The time interval between (S704) and the suction operation C (S715) is shortened.

Also, the count of the number of suction operations D is counted after the ink jet recording apparatus is powered on for the first time, and is not initialized as long as the ink jet recording apparatus uses the same recording head. Whether or not the same recording head is used is detected by the recording control unit 22 (see FIG. 1) when the ink jet recording apparatus is powered on, and if a different recording head is used, the suction operation control unit 23 (see FIG. 1), the number of suction operations D is initialized.

As described above, by controlling so that the time interval until the suction operation becomes shorter as the use time of the recording head increases, the same bubble removing ability can always be exerted, so that the recording head is in a normal state. Not only can it be kept at a high level, but the recording head can be operated normally for a longer period of time.

In the second and third embodiments described above, the timing of the suction operation is left up to the ink jet recording apparatus, but a mode in which the user can select the method of using the recording head is set. You may. If the user requires a higher throughput than the long life of the print head, the suction operation timing can be delayed within a range where normal printing can be performed by reducing the dot count coefficient a and the leaving time coefficient b. On the contrary, when it is desired to extend the life of the print head, the dot count coefficient a is increased to accelerate the suction operation timing, or a stop process of waiting until the print head temperature T becomes a certain value or less is performed during the suction operation. For example, the consumption of the recording head can be reduced and the life of the recording head can be extended by adding them. In this mode, the user can arbitrarily select the life extension or high throughput of the recording head, and if nothing is done, automatic suction control is performed by a preset numerical value.

Each of the embodiments described above can also be applied to a color ink jet recording apparatus having a plurality of recording heads for ejecting inks of different colors. In this case, it is preferable to provide a dot counting means and a time counting means for each recording head.

The present invention brings excellent effects particularly in an ink jet type recording head and a recording apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet recording systems.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. 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, liquid (ink)
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which is stored, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling. , It is effective because it generates heat energy in the electrothermal converter and causes film boiling on the heat-acting surface of the recording head, resulting in the formation of bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis. Is. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise of the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which a heat acting portion is arranged in a bending region.

In addition, JP-A-59-123670 discloses a structure in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which an opening corresponds to a discharge portion.

Further, a full line type recording head having a length corresponding to the width of the maximum recording medium which can be recorded by the recording apparatus is a combination of a plurality of recording heads as disclosed in the above-mentioned specification. Either the structure that satisfies the length or the structure as one recording head integrally formed may be used, but the present invention can more effectively exhibit the above-described effects.

In addition, by being mounted on the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording head itself. The present invention is also effective when a cartridge-type recording head provided with an ink tank is used.

Further, it is preferable to add preliminary auxiliary means or the like to the recording head, which is provided as a configuration of the recording apparatus of the present invention, because the effect of the present invention can be further stabilized. Specific examples thereof include a preheating means using an electrothermal converter or a heating element other than this, or a combination thereof, and a preliminary ejection mode in which ejection is performed differently from recording is also performed for stable recording. Is effective for.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for a device provided with at least one of full colors by color mixing.

In the embodiments of the present invention described above, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens at room temperature, or is a liquid, or the above-mentioned liquid. In the inkjet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. Any material that is in liquid form may be used.

In addition, the temperature rise due to the thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or the ink is solidified in a standing state for the purpose of preventing evaporation of the ink. In some cases, such as ink that is liquefied by applying heat energy according to a recording signal and ejected as a liquid ink, or one that has already started to solidify when it reaches a recording medium. The use of an ink having a property of being liquefied only by heat energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Laid-Open No. 60-71260, a mode in which it is opposed to the electrothermal converter in the state of being held as a liquid or solid in the recesses or through holes of the porous sheet. Also good. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the recording apparatus according to the present invention, in addition to one provided integrally or separately as an image output terminal of information processing equipment such as a word processor or a computer, a copying apparatus combined with a reader, and It may take the form of a facsimile machine having a transmission / reception function.

[0057]

As described above, in the suction operation control method for the ink jet recording apparatus and the ink jet recording apparatus according to the present invention, the ink in the recording head for removing the air bubbles in the recording head is sucked from the recording head. By performing it based on the number of ejection dots, the recording head leaving time, and the temperature of the recording head, the suction operation can be performed at an optimum time according to the temperature of the recording head. As a result, the number of suction operations is minimized, and the throughput of the printing apparatus can be minimized while keeping the printhead in an optimum state.

Further, the suction amount of ink in the recording head is
By changing the number of dots ejected from the recording head, the leaving time of the recording head, and the temperature of the recording head,
The amount of ink consumed by the suction operation is suppressed, and the running cost can be reduced.

Furthermore, by shortening the interval of the suction operation for sucking the ink in the recording head as the use time of the recording head increases, even if the deterioration of the recording head due to the use of the recording head progresses, similar bubble removal is always performed. Since the ability can be exhibited, not only can the recording head be kept in a normal state, but also the recording head can be normally operated for a longer period of time.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the configuration of an embodiment of an inkjet recording apparatus of the present invention.

FIG. 2 is a perspective view of a main part of a recording head of the inkjet cartridge shown in FIG.

FIG. 3 is a flowchart of a first embodiment of a suction operation control method for an inkjet recording apparatus according to the present invention.

FIG. 4 is a table showing an example of suction dot counter values and suction leaving time counter values for various average print heads used for the suction operation control shown in FIG.

FIG. 5 is a flowchart of a second embodiment of a suction operation control method for an inkjet recording apparatus of the present invention.

6 is a table showing an example of a suction amount with respect to a suction parameter V in the suction operation B shown in FIG.

FIG. 7 is a table showing an example of the dot count coefficient and the leaving time coefficient with respect to the number of times of the suction operation when the dot count coefficient and the leaving time coefficient are changed according to the number of suction operations.

FIG. 8 is a graph showing the relationship between the volume of bubbles generated in the recording head and the number of recording dots.

FIG. 9 is a graph showing the relationship between the volume of bubbles generated in the recording head and the standing time.

[Explanation of symbols]

 1 Inkjet Cartridge 1a Discharge Port Surface 1b Discharge Port 1c Common Liquid Chamber 1d Liquid Path 1e Electrothermal Converter 2 Carriage 3 Paper Holding Plate 4 Platen 5 Lead Screw 5a Spiral Groove 6 Lever 7, 8 Photocoupler 9, 10 Transmission Gear 11 Drive Motor 12 Suction means 13 Cap member 14 Cap support member 15 Cleaning blade 16 Blade support member 21 Temperature sensor 22 Recording control means 23 Suction operation control means 24 Time counting means 25 Dot counting means 30 Recording paper

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location B41J 2/125 9012-2C B41J 3/04 104 K (72) Inventor Kentaro Yano Shimomaruko Ota-ku, Tokyo 3-30-2 Canon Inc. (72) Inventor Kiichiro Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Iwasaki 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc. (72) Inventor Hitoshi Nishikori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (12)

[Claims] 1. The ink in the recording head is sucked at a predetermined timing in order to remove bubbles generated in the recording head for recording by ejecting ink.
In the suction operation control method for an inkjet recording apparatus, the predetermined timing is determined based on the number of dots ejected from the recording head, the leaving time of the recording head, and the temperature of the recording head. A method for controlling a suction operation of an inkjet recording apparatus. 2. The predetermined timing is such that the number of dots ejected from the recording head and the leaving time of the recording head when ejection defects due to the bubbles occur with respect to various temperatures of the recording head are obtained in advance. During recording, while detecting the temperature of the recording head, the number of ejection dots exceeds the number of ejection dots obtained for the detected temperature, or the leaving time is for the detected temperature. 2. The suction operation control method for an ink jet recording apparatus according to claim 1, wherein a timing that exceeds a required standing time, whichever is earlier, is set. 3. The suction amount of ink in the recording head is
The suction operation control method for an inkjet recording apparatus according to claim 1, wherein the number of dots ejected from the recording head, the leaving time of the recording head, and the temperature of the recording head are changed. 4. The suction operation control of an ink jet recording apparatus according to claim 1, 2 or 3, wherein an interval of a suction operation for sucking ink in the recording head is shortened in accordance with an increase in use time of the recording head. Method. 5. The recording head comprises an electrothermal converter for generating thermal energy for ejecting ink.
The suction operation control method for an inkjet recording apparatus according to claim 1, 2, 3, or 4. 6. The ink jet recording apparatus according to claim 5, wherein the recording head ejects ink from an ejection port by utilizing film boiling generated in ink by thermal energy applied by the electrothermal converter. Suction operation control method. 7. An ink jet recording apparatus having a recording head for recording by ejecting ink, and a suction means for sucking ink in the recording head to remove air bubbles generated in the recording head, Dot counting means for counting the number of dots ejected from the recording head, time counting means for counting the leaving time of the recording head, temperature detecting means for detecting the temperature of the recording head, and counting by the dot counting means. And a suction operation control means for sending a suction operation command to the suction means based on the number of ejected dots, the leaving time counted by the time counting means, and the temperature detected by the temperature detecting means. Characteristic inkjet recording device. 8. The suction operation control means determines whether the number of discharge dots counted by the dot count means is a discharge failure due to the bubbles with respect to the temperature of the recording head detected by the temperature detection means which is obtained in advance. At the time when the number of ejected dots is exceeded when it is generated, or when the standing time counted by the time counting means is
A suction operation command is given to the suction means at a time point which is earlier than a time point, which is obtained in advance, with respect to the temperature of the recording head detected by the temperature detection means when the ejection failure due to the bubbles occurs, whichever is earlier. The ink jet recording apparatus according to claim 7, wherein the ink jet recording apparatus is for sending. 9. The suction operation control means, the number of ejection dots counted by the dot counting means,
8. The amount of suction of the ink in the recording head by the suction unit is changed according to the standing time counted by the time counting unit and the temperature detected by the temperature detecting unit. 8. The inkjet recording device according to item 8. 10. The suction operation control means controls the time interval for sending a suction operation command to the suction means so as to be shortened in accordance with an increase in the usage time of the recording head. The ink jet recording apparatus according to item 8, 8 or 9. 11. The inkjet recording apparatus according to claim 7, wherein the recording head includes an electrothermal converter for generating thermal energy for ejecting ink. 12. The ink jet recording apparatus according to claim 11, wherein the recording head ejects the ink from an ejection port by utilizing film boiling generated in the ink by thermal energy applied by the electrothermal converter.