JP3891235B2 - Flushing control method in ink jet recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus that has a recording head that moves in the width direction of a recording sheet and prints an image on the recording sheet by ejecting ink droplets toward the recording sheet based on print data. More particularly, the present invention relates to a technique for improving a control sequence of a flushing control means for preventing clogging of nozzle openings of a recording head.
[0002]
[Prior art]
Since graphic processing can be executed relatively easily with the development of personal computers, there is a need for a recording apparatus capable of outputting, for example, a hard copy of a color image displayed on a display with high quality. In order to meet such a demand, a recording apparatus equipped with an ink jet recording head is provided. This ink jet recording apparatus has a relatively low noise during printing and can form small dots with a high density, and is used in many printing including color printing in recent years.
[0003]
Such an ink jet recording apparatus includes an ink jet recording head that receives ink supplied from an ink cartridge, and a paper feeding unit that moves the recording paper relative to the recording head, and the recording head responds to a print signal. Recording is performed by forming dots by ejecting ink droplets onto the recording paper while moving. A recording head capable of ejecting black, yellow, cyan, and magenta inks is provided in a common head holder, enabling full-color printing by changing the ejection ratio of each ink as well as text printing with black ink. .
[0004]
In such an ink jet recording head, printing is performed by ejecting ink pressurized in a pressure generating chamber as ink droplets from a nozzle onto a recording sheet, and therefore, an increase in ink viscosity due to evaporation of a solvent from a nozzle opening or In addition, there is a problem that the nozzle opening is clogged due to solidification of ink, adhesion of dust, and mixing of bubbles, resulting in poor printing.
[0005]
For this purpose, the ink jet recording apparatus usually includes a capping unit for sealing the nozzle openings of the recording head during non-printing, and a cleaning device for cleaning the nozzle plate as necessary. This capping means not only functions as a lid for preventing the ink of the nozzle opening from drying, but also when the nozzle opening is clogged, the nozzle plate is sealed with a cap member, It also has a function of eliminating the clogging of the nozzle openings by sucking ink from the nozzle openings by the negative pressure.
[0006]
The forcible ink ejection process to eliminate clogging of the recording head is usually called a cleaning operation. When printing is resumed after a long pause of the machine, the user also eliminates clogging of the recording head. This process is executed when the cleaning switch is pressed to perform a wiping operation with a cleaning member made of an elastic plate such as rubber after discharging ink droplets.
[0007]
Also, it has a function to eject ink droplets by applying a drive signal unrelated to printing to the recording head, which is usually called a flushing operation, and is uneven in the vicinity of the nozzle opening of the head by wiping or the like during the cleaning operation. This operation is performed at regular intervals for the purpose of recovering the meniscus and preventing clogging due to ink thickening at the nozzle openings where ink droplets are less discharged during printing.
[0008]
[Problems to be solved by the invention]
By the way, in the ink jet recording apparatus as described above, the nozzle opening of the recording head is sealed by the capping unit when not printing or when the operation power to the recording apparatus is not turned on (power off state). It is configured. However, even if the nozzle opening is sealed by the capping means, the ink at the nozzle opening portion of the recording head thickens due to the evaporation of the solvent of the ink, causing the nozzle opening to be clogged, resulting in a printing defect. Arise.
[0009]
Therefore, in the conventional recording apparatus, when the operation power is turned on, a sequence in which the cleaning operation or the flushing operation is performed by determining the elapsed time after the previous cleaning operation is performed. In other words, the elapsed time in this case is set to a relatively short time, and after the elapsed time, the operation of recovering the clogging of the nozzle opening is always performed by executing a sequence of cleaning operations.
[0010]
However, in the cleaning operation, the head is sealed by the capping unit, and the main suction step for sucking a relatively large amount of ink, the step of opening the valve communicating with the capping unit and discharging the sucked ink to the waste ink tank. , A step of sucking a small amount of ink again so as not to bubble bubbles entering from the nozzle of the head, a step of opening the valve and discharging the sucked ink to the waste ink tank, and a finish to recover the irregular meniscus in the head A series of cleaning sequences are completed after passing through a small amount suction step, an ink discharging step, and a waiting time for waiting for the spontaneous disappearance of extremely small bubbles that have entered from the nozzles.
[0011]
Therefore, it takes at least one minute or more to execute these series of cleaning sequences, which causes the user to wait for a considerable waiting time after power-on. And has the problem of giving mental annoyance. In addition, in the cleaning sequence described above, the effect of ink bubbling in the internal space of the capping device cannot be removed despite the small amount of suction step and the weighting step for finishing, and printing defects such as missing dots can occur. There is also a problem that it is difficult to ensure sufficient reliability.
[0012]
Further, since a relatively large amount of ink is sucked by the negative pressure, the amount of ink consumed is large, and there is a problem that the life of the ink cartridge is shortened and the running cost is increased. Furthermore, since the pump for applying a negative pressure to the capping means is driven, there is a problem that a relatively loud operation sound is generated during a standby time when the power is turned on, which causes anxiety to the user.
[0013]
In view of such problems, the inventors have focused on the fact that among a plurality of types of ink, for example, black ink and color ink differ in the degree of thickening at the same elapsed time, and dot missing Has found a means to effectively eliminate the occurrence of printing defects due to thickened ink by a flushing operation that does not easily occur, etc. It is an object of the present invention to provide a highly reliable recording apparatus that can suppress the occurrence of the above. Another object of the present invention is to provide a high-commercial value recording apparatus that can suppress unnecessary ink consumption due to a cleaning operation and can suppress generation of noise associated with driving of a suction pump when power is turned on. To do.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a flushing control method in an ink jet recording apparatus according to the present invention includes a plurality of ink jet recording heads for ejecting ink droplets from nozzle openings, and nozzle openings of the recording heads. A flushing control method for an ink jet recording apparatus, comprising a plurality of capping means corresponding to each recording head to be sealed, and configured to eject ink droplets from the nozzle openings to the capping means in response to a flushing command signal. In addition, among the recording heads that handle printing inks other than the printing inks that are most likely to be thickened in response to the flushing command signal, the printing inks that are likely to be thickened are handled from the nozzle openings of at least one recording head. Ink is ejected to the capping means corresponding to the recording head. A first flushing step, a capping step for sealing a nozzle opening of a recording head that handles printing ink that tends to thicken with a capping means that has received ink discharged by the first flushing step, and the printing ink that tends to thicken A standby step of waiting while the nozzle opening of the recording head to be handled is sealed by the capping means, and a printing ink from the recording head that handles printing ink other than the printing ink discharged in the first flushing step to the capping means. On the other hand, the second flushing step of discharging is sequentially performed.
[0015]
In this case, according to the flushing control method of the ink jet recording apparatus using black, yellow, magenta, and cyan as the printing ink, the printing ink other than the printing ink that is most likely to thicken in response to the flushing command signal. In this case, all the inks of yellow, magenta and cyan, or two of them, or one of them are controlled to be ejected from the nozzle openings to the capping means corresponding to the black print recording head.
[0016]
The flushing control method in the ink jet recording apparatus according to the present invention is compatible with a plurality of ink jet recording heads that eject ink droplets from the nozzle openings and the recording heads that seal the nozzle openings of the recording heads. A flushing control method for an ink jet recording apparatus, comprising a plurality of capping means, and configured to eject ink droplets from the nozzle openings to the capping means by a flushing command signal. A first flushing step for ejecting ink from a nozzle opening of a recording head handling printing ink that is most difficult to thicken, to a capping unit corresponding to the recording head handling printing ink that is most likely to thicken; Recording heads that handle printing inks that tend to stick The capping step of sealing the ink opening with the capping unit that has received the ejected ink by the first flushing step, and the nozzle opening of the recording head that handles the printing ink that tends to thicken are kept waiting with the capping unit sealed. The standby step and the second flushing step of ejecting the printing ink to the capping means from the recording head handling the printing ink other than the printing ink ejected in the first flushing step are sequentially executed. .
[0017]
In this case, in the flushing control method of the ink jet recording apparatus using black, yellow, magenta, and cyan as printing inks, yellow, magenta, and printing inks that are hardest to thicken in response to the flushing command signal are received. Control is performed so that any one kind of cyan ink is ejected from the nozzle opening to a capping unit corresponding to the black print recording head.
[0018]
In any of the above-described methods, in the first flushing step, the position of the nozzle opening of the recording head of the printing ink that is hard to thicken with respect to the capping unit that receives the ink discharge is sealed in the capping step. Control is performed so that the nozzle openings of the recording head of the printing ink that tends to thicken in the state are opposed to each other.
[0019]
The flushing control method in the ink jet recording apparatus according to the present invention includes a recording head that ejects ink droplets from a plurality of rows of nozzle openings that handle a plurality of types of printing ink, and a capping that seals the nozzle openings of the recording head. A flushing control method for an ink jet recording apparatus, which is configured to discharge ink droplets from the nozzle opening to the capping means by a flushing command signal, and a plurality of types of printing are received upon receiving the flushing command signal A first flushing step in which printing ink other than the printing ink that is most likely to thicken is ejected from the nozzle opening to the capping means, and the nozzle opening of the recording head is sealed by the capping means. A capping step and the recording head; A standby step for waiting while the nozzle openings of the nozzles are sealed by the capping unit and a second flushing step for discharging printing ink other than the printing ink discharged in the first flushing step to the capping unit are sequentially executed. To be made.
[0020]
In this case, according to the flushing control method of the ink jet recording apparatus using black, yellow, magenta, and cyan as the printing ink, the printing ink other than the printing ink that is most likely to thicken in response to the flushing command signal. As a control, all the inks of yellow, magenta and cyan, or two of them, or one of them are discharged to the capping means.
[0021]
Further, the flushing control method in the ink jet recording apparatus according to the present invention includes a recording head that discharges ink droplets from a plurality of rows of nozzle openings that handle a plurality of types of printing ink, and a capping that seals the nozzle openings of the recording head. A flushing control method for an ink jet recording apparatus, which is configured to discharge ink droplets from the nozzle opening to the capping means by a flushing command signal, and a plurality of types of printing are received upon receiving the flushing command signal A first flushing step in which only the printing ink, which is hardest to thicken, is ejected from the nozzle opening to the capping unit, and a capping step in which the nozzle opening of the recording head is sealed by the capping unit; Nozzle opening of the recording head And a second flushing step in which printing ink other than the printing ink ejected in the first flushing step is ejected to the capping unit. Made.
[0022]
In this case, in the flushing control method of the ink jet recording apparatus using black, yellow, magenta, and cyan as printing inks, yellow, magenta, and printing inks that are hardest to thicken in response to the flushing command signal are received. Control is performed so that any one kind of cyan ink is ejected to the capping means.
[0023]
Further, in this case, in the first flushing step, the position of the nozzle opening of the printing ink which is hard to increase the viscosity with respect to the capping unit is opposed to the nozzle opening of the printing ink which is easily increased in the sealed state in the capping step. Controlled to be in position.
[0024]
Further, in the ink jet recording apparatus controlled as described above, the capacity of the ink cartridge corresponding to the printing ink ejected in the first flushing step is preferably larger than the ink cartridges of the other printing inks. Composed.
[0025]
In the ink jet recording apparatus according to the present invention, an ink jet recording head that discharges ink droplets from the nozzle opening and a capping unit that seals the nozzle opening of the recording head are mounted, and the nozzle opening is received by a flushing command signal. An ink jet type recording apparatus configured to eject ink droplets to the capping unit, and receives flushing command signals to supply flushing dedicated ink other than printing ink to the capping unit from the nozzle opening. There may be a case where a control means for discharging is provided.
[0026]
A preferred flushing control method in this case includes a plurality of ink jet recording heads that eject ink droplets from nozzle openings, and a plurality of capping means corresponding to the respective recording heads that seal the nozzle openings of the recording heads. It is configured to eject ink droplets from the nozzle opening to the capping means by a flushing command signal, and it is the most increased than the nozzle opening of the recording head that receives flushing command signal and handles flushing dedicated ink other than printing ink. A first flushing step for ejecting ink to a capping unit corresponding to a recording head that handles printing ink that tends to be viscous, and a nozzle opening of the recording head that handles printing ink that is most likely to thicken are formed by the first flushing step. Capping means that receives discharged ink Therefore, a capping step for sealing, a standby step for waiting while the nozzle openings of the recording head handling the ink for printing that tends to thicken are sealed by the capping means, and the flushing-dedicated ink ejected in the first flushing step The second flushing step of discharging the printing ink to the capping unit from the recording head handling other printing inks is sequentially executed.
[0027]
In another preferred flushing control method in this case, a recording head that discharges ink droplets from a plurality of nozzle openings that handle a plurality of types of ink, and a capping unit that seals the nozzle openings of the recording head are mounted. In response to the flushing command signal, ink droplets are ejected from the nozzle opening to the capping unit. Upon receiving the flushing command signal, the flushing dedicated ink other than the printing ink is supplied from the nozzle opening to the capping unit. A first flushing step for ejecting ink, a capping step for sealing the nozzle openings of the recording head by a capping means, a standby step for waiting while the nozzle openings of the recording head are sealed by a capping means, 1st flashin And a second flushing step of ejecting printing ink other than the flushing dedicated ink ejected in the capping step to the capping means.
[0028]
In the first flushing step according to the flushing control method described above, the position of the nozzle opening of the flushing dedicated ink with respect to the capping means that receives the ink discharge is easily increased in viscosity while being sealed in the capping step. Control is performed so that the openings are located at opposite positions.
[0029]
In the above-described apparatus and control method, it is preferable to use glycerin diluted with pure water as the flushing dedicated ink. Further, it is preferable that the above-described control methods sequentially execute the steps when the operation power of the recording apparatus is turned on or before printing is started.
[0030]
And, in the case of adopting any of the above control methods, as a preferred embodiment, an ink jet recording head that discharges ink droplets from a nozzle opening, a capping unit that seals the nozzle opening of the recording head, A suction pump for supplying negative pressure to the capping means, a cleaning control means for sucking ink from the nozzle opening of the recording head via the capping means, and a cleaning control means after the cleaning control means performs cleaning. A flushing control means for an ink jet recording apparatus, comprising: a post-cleaning elapsed time detection means for detecting time; and an accumulated open time detection means for detecting the accumulation of time that the recording head is released from the capping means is used. , The first flushing step Number of ejections of definitive ink droplet is controlled to a number corresponding to the time length detected by the detected time length and the accumulated open time detection means in the cleaning after the elapsed time detecting means.
[0031]
Further, in the case of adopting any of the above control methods, as another preferred embodiment, an ink jet recording head that discharges ink droplets from the nozzle openings, and a capping unit that seals the nozzle openings of the recording head, A cleaning pump that supplies negative pressure to the capping unit, a cleaning control unit that sucks ink from the nozzle opening of the recording head via the capping unit, and cleaning performed by the cleaning control unit. A flushing control means for an ink jet recording apparatus, comprising: a post-cleaning elapsed time detection means for detecting a time from a recording time; and a cumulative open time detection means for detecting a cumulative amount of time that the recording head is released from the capping means. Used in the waiting step Machine time is controlled to a time corresponding to the time length detected by the length of time and the accumulated open time detection means detected by the cleaning after the elapsed time detecting means.
[0032]
According to the ink jet recording apparatus configured as described above and the flushing control method thereof, an ink other than the ink that is most easily thickened among the plurality of types of printing inks upon receipt of the flushing command signal, or the ink that is most difficult to thicken. Only the nozzle is discharged from the nozzle opening to the capping device. Further, when a flushing command signal is received, the flushing exclusive ink other than the printing ink is ejected from the nozzle opening to the capping means.
[0033]
As a result, the capping device is wetted by the ink that is difficult to thicken or the ink dedicated to flushing, and in the subsequent step, the capping unit handles the ink that tends to thicken by the capping means, and waits for a predetermined time. The thickened ink adhering to the nozzle surface of the recording head can be softened or dissolved. Therefore, by adding an ejection signal (flushing command) to the recording head that subsequently ejects ink that tends to thicken, the ink in the thickened state is separated from the nozzle opening and the nozzle surface and restored to a normal printable state. Can do.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an ink jet recording apparatus employing a flushing control method according to the invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is a perspective view showing an entire inkjet recording apparatus to which the present invention is applied. In FIG. 1, reference numeral 1 denotes a carriage, which is guided by a timing belt 2 that reciprocates by driving of a carriage motor 3. It is configured to be guided by the member 4 and reciprocated in the axial direction of the platen 5.
[0035]
A black recording head 7 and a color recording head 8 are mounted on the side of the carriage 1 that faces the recording paper 6, and a black ink cartridge 9 that supplies ink to each recording head is provided above the recording head 8. A color ink cartridge 10 is detachably loaded.
[0036]
Reference numeral 11 in the figure denotes a capping device as a capping means arranged outside the non-printing area, and is mounted with a black head cap unit 37 and a color head cap unit 38. A suction pump 12 for applying a negative pressure to the capping device 11 is disposed below the capping device 11.
[0037]
The cap units 37 and 38 function as cap means for preventing the nozzle opening from being dried during the rest period of the recording apparatus, and also function as ink receivers during the flushing operation, and the negative pressure from the suction pump 12 is applied to the recording head. 7 and 8 is also used as a means for sucking ink.
[0038]
FIG. 2 shows an example of an actuator unit in the color recording head 8 described above. Three piezoelectric vibrators 13 are arranged on the nozzle plate 14 and are not shown in FIG. Ink supply channels 20a to 20f that are independent for each nozzle opening row are provided between the piezoelectric vibrators 13 and the nozzle plate 14 so that different color inks can be ejected from nozzle opening rows that will be described later. Is provided.
[0039]
With this configuration, a printing control signal is applied to each piezoelectric vibrator 13, whereby yellow, cyan, and magenta inks supplied to the ink supply channels 20 a to 20 f are ejected from the nozzle opening rows, respectively. Is printed in color. Although not shown, the black recording head 7 has substantially the same configuration as the color recording head 8 described above.
[0040]
3 (a) and 3 (b) show the overall configuration of the capping device 11, (b) is a perspective view of the capping device 11 viewed from one direction, and (b) is a view of (b). It is the perspective view seen from the back direction. Reference numeral 22 in the drawing is a slider, which is connected to the base 21 by a freely rotating arm 23 and a spring 31. When the carriage 1 moves to the non-printing area side and comes into contact with the flag piece 25, the carriage It is configured to move following the movement of 1. A valve unit 28 is fixed to the slider 22, and a valve 29 for opening and closing the valve unit 28 is fixed to the base 21 via a compression spring 30.
[0041]
The flag piece 25 has a convex piece 26 at the lower end, and is configured to abut against the inclined guide surface 24 formed on the base 21 and slide on the surface thereof. A guide surface 32 is also provided on the side portion on the printing area side, and a protrusion 33 protruding in the horizontal direction on the slider 22 is configured to slide on the surface thereof. By the action of these two guide surfaces 24 and 32, the slider 22 can be moved up and down while maintaining a substantially horizontal posture.
[0042]
That is, when the carriage 1 moves to the non-printing region side, the slider 22 moves obliquely upward in conjunction with the movement of the carriage 1, thereby performing a capping operation in which a cap member described later and the nozzle plate surface of the recording head are in close contact with each other. It is configured to be made.
[0043]
The cap unit mounting portion 36 of the slider 22 is connected to the slider 22 by a spring 34 and a protrusion 35, and can be slightly rotated around the protrusion 35. The cap units 37 and 38 are fixed to the slider 22 via compression springs 39, respectively. Therefore, during the capping operation, the adhesion between the cap and the nozzle plate is always kept good.
[0044]
Each of the cap units 37 and 38 is formed with an ink suction port 18 at a lower bottom portion thereof, and is connected to the suction pump 12 shown in FIG. 1 through a tube (not shown) having excellent ink resistance. In addition, each of the cap units 37 and 38 is provided with an air opening 19 on one side surface, and the other ends of the tubes 27 whose one ends are connected to the air opening 19 are connected to the valve unit 28, respectively. Yes.
[0045]
With the above configuration, when the carriage 1 moves to the non-printing area side, the carriage 1 comes into contact with the flag piece 25 as described above, and as a result, the slider 22 moves obliquely upward, and the cap units 37 and 38 are moved to the recording head. The nozzle plate surface is capped. Then, when the slider 22 is positioned on the non-printing area side (home position), the valve unit 28 comes into contact with the valve 29 and the atmosphere opening port 19 is closed. In this state, by supplying negative pressure from the suction pump 12 to the inside of the cap, ink can be sucked from the nozzle openings of the recording head.
[0046]
FIG. 4 is a sectional view showing a state in which the color recording head 8 is capped by the color head cap unit 38, and FIG. 5 shows the cap unit 38 as seen from above. . FIG. 4 is a cross-sectional view taken along the line AA in FIG.
[0047]
The color recording head 8 is positioned above the capping device during the cleaning operation and the flushing operation, and the nozzle plate 14 is capped by the capping device. Nozzle openings 15 are arranged in the nozzle plate 14, and each of yellow, magenta, and cyan inks is ejected by the action of the piezoelectric element 13 disposed corresponding to each nozzle opening 15. .
[0048]
The cap unit 38 is a cup-shaped cap case 40 having an open upper surface, and a cup-shaped member that is housed in the cap case 40 and formed of an elastic member such as a flexible material having ink resistance, particularly rubber. The cap member 16 is configured. The cap member 16 is formed so that its upper edge protrudes slightly from the cap case 40. An ink absorbing material 17 made of a porous material excellent in ink resistance and ink absorbing property is inserted into the inner bottom portion of the cap member 16 so as to substantially cover the bottom surface.
[0049]
An air release port 19 for opening the inside of the cap member 16 to the atmosphere is provided in a substantially central portion of one side surface of the cap member 16 so as to penetrate the thick portion of the cap member 16. The through hole is formed with an inclination so as to gradually decrease toward the ink absorbing material 17, and the opening on the inner surface side of the cap member 16 is positioned above the surface of the ink absorbing material 17. Is formed. The air opening 19 is connected to the valve unit 28 via the tube 27 as described above.
[0050]
Further, as shown in FIG. 5, an ink suction port 18 is formed at the substantially bottom bottom portion of the cap member 16 and is connected to the suction pump 12 through a tube (not shown) as described above.
[0051]
Next, FIG. 6 shows an example of a control circuit mounted on the recording apparatus having the above-described configuration. The recording heads 7 and 8, the ink cartridges 9 and 10, and the valve unit 28 (two valve units are shown as 28A and 28B in FIG. 6) already described with reference to FIG. Therefore, the description is omitted.
[0052]
In FIG. 6, reference numeral 50 denotes a print control means, which generates bitmap data based on print data from the host computer of the recording apparatus, and generates a drive signal by the head drive means 51 based on this data to record. Ink is ejected from the heads 7 and 8. The head drive unit 51 is configured to receive a flushing command signal and output a drive signal for the flushing operation to the recording heads 7 and 8 in addition to the drive signal based on the print data.
[0053]
Reference numeral 52 denotes a cleaning control means, which controls the pump drive means 55 by signals from a cleaning (hereinafter also referred to as CL) command detection means 53, a post-CL elapsed time detection means 54 and a cumulative release time detection means 59, The suction pumps 12A and 12B are controlled.
[0054]
Here, the post-CL elapsed time detection means 54 receives a cleaning end signal from the cleaning control means 52 immediately after the cleaning is executed by the cleaning control means 52, and measures the elapsed time after cleaning. The accumulated release time detection means 59 measures the accumulation of the time when the print head is released from the capping means for printing by the print control means 50, and measures the time when the print head is released from the capping means. Starts and stops timing when printing is finished and the recording head is capped. The cumulative open time detecting means is reset when cleaning is performed by the cleaning control means 52 or when a flushing command is issued from the print control means 50 for a long time during the printing operation.
[0055]
Reference numeral 56 denotes a flushing control means, which is immediately before the printing operation is started, or when the flushing command is output from the printing control means 50 for a certain period of time or when the suction from the cleaning control means 52 is finished. When a signal is output and a time-up signal from a flushing hold timer 57, which will be described later, is output, or when the operation power of the recording apparatus is turned on, the recording heads 7 and 8 are turned on by the print control means 50. By moving to a flushing position, that is, a capping position, a predetermined number of ink droplets are ejected from the nozzle openings of the recording head 7 or 8 in order to prevent clogging or to eliminate clogging, according to a sequence described later.
[0056]
The flushing hold timer 57 starts the timing operation when the cleaning process is finished, and measures the time corresponding to the time when bubbles generated near the nozzle openings of the recording heads 7 and 8 naturally disappear in the cleaning process. Configured to time up.
[0057]
Reference numeral 58 in FIG. 6 denotes a cleaning command switch provided on the control panel of the case, and the CL command detecting means 53 is pushed by the user to push it on to eliminate clogging of the recording head. Is configured to perform a cleaning operation.
[0058]
Next, the operation of the flushing operation in the recording apparatus configured as described above will be described based on each control flow shown in FIGS. First, FIG. 7 shows a control sequence applied to a recording apparatus provided with independent cap units 37 and 38 corresponding to the black recording head 7 and the color recording head 8 as described above.
[0059]
Prior to the description of this control sequence, the degree of increase in viscosity of the printing ink over time will be described. As described above, black ink and three color inks of yellow, magenta, and cyan are generally used as printing inks. In recent years, in order to improve print quality during color printing, particularly color resolution, in addition to the normal inks of the three colors, light magenta and light cyan have been commercialized.
[0060]
Here, in general, between black ink and color ink, the degree of thickening at the same elapsed time is large for black ink and small for color ink. Therefore, the following description is based on the premise that printing inks having such characteristics are used.
[0061]
As shown in FIG. 7, even when the operating power is turned on (PW / ON) for the recording apparatus (shown as a printer in the figure, the same applies hereinafter), or even when the operating power is on. When the printing operation is about to be started by the printing control means 50, the color recording head 8 is moved to the position of the black head cap unit 37 in step S11.
[0062]
This is achieved by driving the carriage motor 3 and moving the carriage 1 via the timing belt 2 by the action of a host computer mounted on the printing apparatus.
[0063]
In step S12, the color ink is flushed from the color recording head 8 into the black head cap unit 37 (first flushing step). This is accomplished by receiving a timing signal from the host computer and applying a flushing command signal to the head drive means 51 from the flushing control means 56 as shown in FIG.
[0064]
In this case, it is desirable that the color ink ejection position is a position where the nozzle openings face each other in a state where the black recording head is capped by the black cap in step S14 described later. As a result, the inside of the black head cap unit 37 is wetted by the color ink which is hard to thicken.
[0065]
The head driving unit 51 that has received the flushing command signal from the flushing control unit 56 may control to discharge all the three color inks simultaneously, or may discharge only one of the color inks. You may do it. Further, in some cases, control may be performed so that yellow, magenta, and cyan are discharged in order each time the control sequence shown in FIG. 7 is repeated. That is, these three color inks are practically not significantly different from each other in viscosity increase. If there is a difference in the degree of thickening among the three color inks, it is desirable to flush only the ink that is most difficult to thicken.
[0066]
In step S 13, the black recording head 9 is moved to the position of the black head cap unit 37. In this case, the color recording head 8 is also moved to the position of the color head cap unit 38 at the same time. This operation is also achieved by driving the carriage motor 3 and moving the carriage 1 via the timing belt 2 by the action of the host computer as described above.
[0067]
Then, in step S14, capping is performed on the heads 7 and 8 by the cap units 37 and 38 (capping step). As described with reference to FIG. 3, when the carriage 1 moves to the non-printing area side, the slider 22 moves obliquely upward in conjunction with the movement of the carriage 1 so that the cap member and the nozzle plate surface of the recording head are moved. Close contact and capping operation is performed.
[0068]
In this way, after capping is performed, a standby state is set in step S15 (Wait = waiting step). During this period, the thick black ink adhered to the nozzle surface of the black ink recording head 7 acts to soften or dissolve.
[0069]
After the ink adhering to the nozzle surface or the like of the black ink recording head 7 is changed from the thickened state to the softened or dissolved state in this way, in step S16, flushing for discharging the black ink from the black ink recording head 7 is performed. (Second flushing step). By this second flushing step, the black ink recording head 7 is restored to perform a normal recording action. At this time, flushing for discharging color ink from the color ink recording head 8 may be performed at the same time.
[0070]
The flushing operation at this time is also performed by receiving a timing signal from the host computer and applying a flushing command signal to the head driving unit 51 from the flushing control unit 56 as described above.
[0071]
By passing through the control sequence as described above, the flushing process when the operation power is supplied to the recording apparatus or before the printing operation is started is completed. In this case, the rise time from when the operation power is turned on to the printable state is about 10 to 30 seconds, so that the printing operation can be performed in a much shorter time than when the cleaning operation is performed.
[0072]
Next, the sequence shown in FIG. 8 shows an example applied to a recording apparatus constituted by a recording head having a black nozzle row and a color nozzle row and one common cap unit corresponding to these nozzle rows.
[0073]
In FIG. 8, when a printing operation is started by the printing control means even when the operation power is turned on or even when the operation power is turned on, the ink other than the ink that is most likely to thicken in step S21. Flushing into one common cap unit (first flushing step). For example, all the inks of yellow, magenta and cyan, or two of them or one of them as inks other than the ink which is most likely to thicken in a printing apparatus using black, yellow, magenta and cyan as printing inks Is discharged from the nozzle opening to the capping means.
[0074]
In this case, it is desirable that the color ink ejection position is a position where the black nozzle openings face each other in the capped state in step S22 described later. As a result, the common cap unit is wetted by the color ink other than the ink that is most likely to thicken. In this case, it is desirable that the capacity of the ink cartridge corresponding to the printing ink ejected in the first flushing step is configured to be larger than the ink cartridges of the other printing inks.
[0075]
In step S22, the recording head is capped by the cap unit (capping step). This capping action is the same as step S14 in FIG.
[0076]
Subsequently, in step S23, a standby state is set (standby step). This step S23 is also the same as step S15 described in FIG. 7, and acts to soften or dissolve the thickened black ink adhered to the nozzle surface of the black ink recording head during this time.
[0077]
In step S24, ink other than the ink ejected in the first flushing step is flushed (second flushing step). The action that occurs in this case is the same as in step S16 described in FIG. 7, and the black ink recording head is restored to perform a normal recording action by this second flushing step. At this time, flushing for discharging the color ink may be simultaneously performed from the color ink recording head.
[0078]
Next, the sequence shown in FIG. 9 is another example applied to a recording apparatus constituted by a recording head having a black nozzle row and a color nozzle row and one common cap unit corresponding to these nozzle rows in the same manner as described above. Indicates. In the sequence shown in FIG. 9, step S31 is different from the sequence shown in FIG. 8, and the steps after step S32 are the same as those after step S22 described in FIG.
[0079]
That is, in step S31, only the ink that is most difficult to thicken is flushed (first flushing step) into one common cap unit. For example, the ink that is most difficult to thicken is any of yellow, magenta, and cyan. One kind of ink is flushed into the capping unit from the nozzle opening. In this case, it is desirable that the discharge position of the ink that is most difficult to thicken is the position where the nozzle openings of the ink that are most likely to thicken in the capped state in step S32 face each other. In addition, it is desirable that the ink cartridge capacity of the printing ink to be flushed in the first step is set to be larger than that of the other printing ink.
[0080]
Subsequently, in step S34, ink other than the ink ejected in the first flushing step is flushed (second flushing step). Accordingly, by passing through the sequence shown in FIG. 9, the black ink recording head, for example, recovers to perform a normal recording action, similarly to the case shown in FIG.
[0081]
Next, the sequence shown in FIG. 10 is applied to a recording apparatus in which a black recording head and a color recording head capping device are provided independently, and an example in which a flushing ink other than printing ink is used. Show. As the flushing ink, for example, glycerin diluted with pure water can be used. Further, a flushing head different from the recording head may be prepared for flushing the flushing ink, or for example, one of the two nozzle rows of the black head is used for flushing the dedicated ink. You may do it.
[0082]
In step S41 shown in FIG. 10, the head from which the flushing ink is ejected (the flushing head) is moved to the black cap unit position. In step S42, the flushing ink is flushed into the black cap unit from the head from which the flushing ink is discharged. In this case, the discharge position of the flushing dedicated ink with respect to the cap unit is a position facing the nozzle opening of the recording head that discharges the most viscous printing ink, that is, the black ink, in the capped state in step S44 described later. It is desirable to be.
[0083]
As a result, the cap unit is wetted with the flushing ink. In step S43, the black ink head is moved to the cap unit position of the black ink head. In step S44 and subsequent step S45, the ink in the thickened state adhering to the black ink head acts to be softened or dissolved. After the ink attached to the black ink recording head is changed from the thickened state to the softened or dissolved state in this way, printing ink is ejected from each recording head in step S46 (second flushing step). As a result, the black ink recording head and the color ink recording head are restored to perform normal recording operation.
[0084]
Next, the sequence shown in FIG. 11 is applied to a recording apparatus including a recording head having a black nozzle row and a color nozzle row, and one common cap unit corresponding to these nozzle rows, and is used only for flushing as described above. An example of using ink is shown.
[0085]
The flushing dedicated ink used in this case is the same as that described in the sequence shown in FIG. In order to flush the dedicated ink, a flushing dedicated head different from the recording head may be prepared in the same manner as described above, or, for example, one of the nozzle rows provided with two rows of black heads is designated as the dedicated ink. It may be used for flushing.
[0086]
In step S51 shown in FIG. 11, the above-described flushing exclusive ink is flushed into the cap unit (first flushing step). In this case, the discharge position of the flushing dedicated ink (or solution) with respect to the cap unit is the nozzle opening of the printing ink that is most likely to be thickened, that is, the nozzle that discharges the black ink, in the capped state in step S52 described later. A position facing the opening is desirable.
[0087]
As a result, the cap unit is moistened by the flushing ink, and the thickened ink attached to the color nozzle row including the black nozzle row in step S52 and subsequent step S53 is softened or dissolved. Act on. After the ink adhering to each nozzle row is changed from the thickened state to the softened or dissolved state in this way, the black ink is ejected from each nozzle row in step S54 (second flushing step). The nozzle array for color and the nozzle array for color ink are recovered so as to perform a normal recording action.
[0088]
The above description is based on the assumption that the degree of thickening at the same elapsed time is large for black ink and small for color ink. However, the degree of thickening for color ink is different from that for black ink. In the case of a large size, it is natural to reverse the above description.
[0089]
Next, FIG. 12 shows the relationship between the desirable number of inks ejected in the first flushing step executed in the recording apparatus of the present invention and the desirable standby time in the standby step.
[0090]
That is, the horizontal axis shown in FIG. 12 indicates the elapsed time (unit: time) after cleaning, and this indicates the elapsed time since the cleaning of the recording apparatus regardless of whether the operation power to the recording apparatus is on or off. Show. The elapsed time after cleaning is measured by the post-CL elapsed time detecting means 54 shown in FIG.
[0091]
In the figure, T2 indicates the cumulative print time, which is the cumulative time (unit: time) that the recording head was released from the capping device for printing, and this is the cumulative open time detection shown in FIG. It is timed by means 59.
[0092]
The left vertical axis in FIG. 12 shows the ideal number of ejections from the head (discharge / 1 nozzle) performed in the first flushing step when the cumulative printing time T2 is used as a parameter. Also, the right vertical axis of FIG. 12 shows the ideal standby time (unit: seconds) in the standby step when the cumulative printing time T2 is also used as a parameter.
[0093]
Therefore, for example, when the elapsed time after CL is 40 hours and the cumulative printing time T2 is between 30 minutes and 1 hour, the relationship shown by the long broken line drawn in the approximate center in the figure is read out. The number of ink ejections required in the first flushing step at this time is a number corresponding to the left vertical axis (for example, about 10,000 shots / 1 nozzle). Further, the standby time required in the standby step at this time is a time corresponding to the right vertical axis (for example, about 9 seconds).
[0094]
These controls are carried out by the flushing control means 56 taking the time measured from the post-CL elapsed time detection means 54 and the cumulative opening time detection means 59 in FIG. 6 and stored in the flushing control means 56. The number of discharges and the waiting time can be calculated by referring to FIG.
[0095]
Note that the above description uses a recording apparatus that uses black ink and three color inks as an example. However, the same effect can be obtained even if the recording apparatus uses light magenta and light cyan in addition to these. Of course, it can be obtained.
[0096]
【The invention's effect】
As is apparent from the above description, in the ink jet recording apparatus and the flushing control method according to the present invention, an ink other than the ink that is most likely to thicken among a plurality of types of printing inks upon receiving a flushing command signal, or Since only the ink that is most difficult to thicken or only the flushing exclusive ink other than the printing ink is controlled to be ejected from the nozzle opening to the capping device, the inside of the capping device can be in a wet state. Therefore, it is possible to soften or dissolve the thickened ink adhering to the nozzle surface of the recording head that handles ink that tends to thicken during the following capping and predetermined waiting time, and normal printing is possible by the flushing action It can be restored to the state.
[0097]
Therefore, by performing this flushing operation when the apparatus is turned on, it is possible to extremely reduce the standby time after turning on the power, and to provide a highly reliable recording apparatus that can suppress the occurrence of printing defects. Can be provided. In addition, it is possible to provide a recording apparatus having a high commercial value that can suppress unnecessary consumption of ink and suppress the generation of noise associated with driving of the suction pump when the power is turned on.
[Brief description of the drawings]
FIG. 1 is a perspective view of an ink jet recording apparatus to which the present invention is applied.
FIG. 2 is a perspective view showing an example of an actuator unit in a recording head mounted on the recording apparatus shown in FIG.
FIG. 3 is a perspective view showing an example of a capping device mounted on the recording apparatus shown in FIG.
4 is a cross-sectional view of the cap unit mounted on the recording apparatus of the present invention taken along line AA in FIG.
5 is a top view of the cap unit shown in FIG. 4. FIG.
FIG. 6 is a block diagram showing an example of a control circuit equipped in the recording apparatus of the present invention.
FIG. 7 is a flowchart showing an example of a first control sequence of a flushing action performed in the recording apparatus of the present invention.
FIG. 8 is a flowchart showing an example of a second control sequence of the flushing action performed in the recording apparatus of the present invention.
FIG. 9 is a flowchart showing an example of a third control sequence of the flushing action performed in the recording apparatus of the present invention.
FIG. 10 is a flowchart showing an example of a fourth control sequence of the flushing action performed in the recording apparatus of the present invention.
FIG. 11 is a flowchart showing an example of a fifth control sequence of the flushing action performed in the recording apparatus of the present invention.
FIG. 12 is a diagram showing a relationship between an ideal number of ink ejections during flushing and an ideal standby time in a standby step performed in the recording apparatus of the present invention.
[Explanation of symbols]
1 Carriage
2 Timing belt
3 Carriage motor
6 Recording paper
7 Black recording head
8 Color recording head
9 Black ink cartridge
10 Color ink cartridge
11 Capping device
12 Suction pump
13 Piezoelectric vibrator
14 Nozzle plate
15 Nozzle opening
16 Cap member
37 Cap unit for black head
38 Color head cap unit
50 Print control means
51 Head drive means
52 Cleaning control means
53 CL command detection means
54 CL elapsed time detection means
55 Pump drive means
56 Flushing control means
57 Flashing hold timer
58 Cleaning command switch
59 Cumulative opening time detection means

Claims (11)

A plurality of ink jet recording heads for ejecting ink droplets from nozzle openings and a plurality of capping means corresponding to the respective recording heads for sealing the nozzle openings of the recording heads are mounted. A flushing control method for an ink jet recording apparatus configured to eject ink droplets from an opening to a capping unit,
Compatible with recording heads that handle printing inks that tend to thicken from the nozzle openings of at least one recording head, among the recording heads that handle printing inks other than printing inks that are most likely to thicken upon receiving a flushing command signal A first flushing step of ejecting ink to the capping means to perform,
A capping step of sealing a nozzle opening of a recording head that handles printing ink that tends to thicken by a capping unit that has received ink discharged by the first flushing step;
A standby step of waiting while the nozzle opening of the recording head that handles the printing ink that tends to thicken is sealed by the capping means;
The second flushing step of ejecting printing ink to the capping unit from the recording head that handles printing ink other than the printing ink ejected in the first flushing step is sequentially performed. A flushing control method in an ink jet recording apparatus.   A flushing control method for an ink jet recording apparatus using black, yellow, magenta, and cyan as printing inks, wherein yellow, magenta are used as printing inks other than the printing ink that is most likely to thicken in response to the flushing command signal. 2. The ink jet recording according to claim 1, wherein all of cyan ink or two of them or one of them is ejected from the nozzle opening to a capping means corresponding to a black printing recording head. Flushing control method in apparatus. A plurality of ink jet recording heads for ejecting ink droplets from nozzle openings and a plurality of capping means corresponding to the respective recording heads for sealing the nozzle openings of the recording heads are mounted. A flushing control method for an ink jet recording apparatus configured to eject ink droplets from an opening to a capping unit,
A first flushing that ejects ink to a capping unit corresponding to a recording head that handles printing ink that is most likely to thicken from a nozzle opening of the recording head that handles printing ink that is most difficult to thicken upon receiving a flushing command signal. Steps,
A capping step of sealing a nozzle opening of a recording head that handles printing ink that is most likely to be thickened by a capping unit that has received ink ejected by the first flushing step;
A standby step of waiting while the nozzle opening of the recording head that handles the printing ink that tends to thicken is sealed by the capping means;
The second flushing step of ejecting printing ink to the capping unit from the recording head that handles printing ink other than the printing ink ejected in the first flushing step is sequentially performed. A flushing control method in an ink jet recording apparatus.   A flushing control method for an ink jet recording apparatus that uses black, yellow, magenta, and cyan as printing inks. When the flushing command signal is received, the most difficult to thicken the printing ink among yellow, magenta, and cyan. 4. The flushing control method for an ink jet recording apparatus according to claim 3, wherein any one kind of ink is ejected from the nozzle opening to a capping unit corresponding to a black print recording head.   In the first flushing step, the position of the nozzle opening of the recording head of the printing ink that is hard to thicken with respect to the capping means that receives the ink discharge is the recording head of the printing ink that tends to thicken in the sealed state in the capping step. 5. The flushing control method for an ink jet recording apparatus according to claim 1, wherein the nozzle openings of the ink jet recording apparatus are controlled to face each other. A recording head that ejects ink droplets from a plurality of rows of nozzle openings that handle multiple types of printing ink and a capping unit that seals the nozzle openings of the recording head are installed, and ink droplets are ejected from the nozzle openings by a flushing command signal. A flushing control method for an ink jet recording apparatus configured to be discharged to a capping unit,
A first flushing step of receiving a flushing command signal and ejecting ink from a plurality of types of printing inks other than the printing ink that is most likely to thicken to the capping means from the nozzle opening;
A capping step of sealing the nozzle openings of the recording head by capping means;
A standby step of waiting while the nozzle opening of the recording head is sealed by the capping means;
A flushing control method for an ink jet recording apparatus, wherein a second flushing step for ejecting printing ink other than the printing ink ejected in the first flushing step to a capping unit is sequentially executed. .   A flushing control method for an ink jet recording apparatus using black, yellow, magenta, and cyan as printing inks, wherein yellow, magenta are used as printing inks other than the printing ink that is most likely to thicken in response to the flushing command signal. 7. The flushing control method in an ink jet recording apparatus according to claim 6, wherein all of cyan ink, or two of them, or one of them is ejected to a capping unit. A recording head that ejects ink droplets from a plurality of rows of nozzle openings that handle multiple types of printing ink and a capping unit that seals the nozzle openings of the recording head are installed, and ink droplets are ejected from the nozzle openings by a flushing command signal. A flushing control method for an ink jet recording apparatus configured to be discharged to a capping unit,
A first flushing step of receiving only a printing ink that is most difficult to thicken among a plurality of types of printing inks in response to a flushing command signal, and ejecting the ink from a nozzle opening to a capping unit;
A capping step of sealing the nozzle openings of the recording head by capping means;
A standby step of waiting while the nozzle opening of the recording head is sealed by the capping means;
A flushing control method for an ink jet recording apparatus, wherein a second flushing step for ejecting printing ink other than the printing ink ejected in the first flushing step to a capping unit is sequentially executed. .   A flushing control method for an ink jet recording apparatus that uses black, yellow, magenta, and cyan as printing inks. When the flushing command signal is received, the most difficult to thicken the printing ink among yellow, magenta, and cyan 9. The flushing control method in an ink jet recording apparatus according to claim 8, wherein any one kind of ink is ejected to the capping unit.   In the first flushing step, the position of the nozzle opening of the printing ink which is hard to thicken with respect to the capping means is positioned so as to face the nozzle opening of the printing ink which is easily thickened in the sealed state in the capping step. The flushing control method for an ink jet recording apparatus according to any one of claims 6 to 9, wherein the flushing control method is performed as described above.   The capacity of the ink cartridge corresponding to the printing ink ejected in the first flushing step is set larger than that of the ink cartridge of the other printing ink, or any one of claims 1 to 4, 10. A flushing control method in an ink jet recording apparatus according to claim 6.

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