JP3712033B2 - Ink jet recording apparatus and ink discharge control method for recording head in the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus that includes 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. The present invention relates to an ink discharge processing control technique 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 (hereinafter also referred to as a printer) 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 supply of ink from an ink cartridge, and a paper feeding unit that moves the recording paper relative to the recording head, and based on the print signal, the recording head Recording is performed by forming dots by ejecting ink droplets onto the recording paper while moving. For example, 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. Yes.
[0004]
The ink jet recording head has a relationship in which ink pressurized in a pressure generating chamber is ejected from a nozzle as ink droplets onto a recording sheet for printing, so that the ink viscosity increases due to evaporation of the solvent from the nozzle opening, There is a problem that the nozzle opening is clogged due to solidification of dust, adhesion of dust, and mixing of air bubbles, resulting in poor printing.
[0005]
For this purpose, the ink jet recording apparatus 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 opening by sucking ink from the nozzle opening by the negative pressure.
[0006]
The forced 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, or when the user clogs the recording head. This process is executed when the cleaning switch is pressed to eliminate the ink drop, and is accompanied by a wiping operation by a cleaning member made of an elastic plate such as rubber after discharging ink droplets by negative pressure.
[0007]
It also has a function of applying a drive signal unrelated to printing to eject ink droplets to the recording head, which is usually called a flushing operation, and is near the nozzle opening of the recording head by wiping or the like during a cleaning operation. This operation is performed at regular intervals in order to recover irregular meniscuses and to prevent clogging due to ink thickening at nozzle openings where ink droplets are less discharged during printing.
[0008]
By the way, in the ink jet recording apparatus as described above, flushing for moisturizing is performed in the cap at the end of printing, and the nozzle opening of the recording head is sealed by the capping means as described above when the apparatus is left. Yes.
[0009]
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, and the nozzle opening is clogged, resulting in a printing defect. Arise.
[0010]
This means that the longer the printing time, the shorter the time for which the ink is left, resulting in a non-ejection state due to the thickening of the ink in the head. Therefore, in this type of conventional recording apparatus, the cleaning operation (timer cleaning) or the flushing operation is performed by the elapsed time after the previous cleaning operation and the accumulated print time at the next power-on or before the start of printing. By doing so, the occurrence of such a problem was avoided.
[0011]
FIG. 13 shows an example of the processing method, showing the elapsed time from the previous cleaning in the horizontal axis direction, and the relationship of the accumulated print time after cleaning in the vertical axis direction. As can be understood from the example shown in the figure, in a state where the elapsed time from the previous cleaning is small and the accumulated print time after cleaning is small, the nozzle opening is clogged to some extent by the flushing operation. Prevention treatment can be achieved.
[0012]
However, as the elapsed time from the previous cleaning increases and the cumulative print time after cleaning increases, the recording head suction operation by the cleaning operation is forced again.
[0013]
In this cleaning operation, the recording head is generally sealed by a capping unit, and a main suction step for sucking a relatively large amount of ink, and a valve communicating with the capping unit is opened to discharge the sucked ink to a waste ink tank. A step of sucking a small amount of ink again so as not to bubble bubbles that have entered from the nozzle openings of the recording head, a step of releasing the valve and discharging the sucked ink to a waste ink tank, and an irregular meniscus in the recording head A series of cleaning sequences is completed after passing through a small amount of finishing suction process to recover the ink, a process of discharging ink, and a process of waiting for the natural disappearance of extremely small bubbles that have entered from the nozzles.
[0014]
Therefore, it takes at least a required time of 1 minute or more to execute the series of cleaning sequences.
[0015]
[Problems to be solved by the invention]
In general, in order to use this type of printer, the operation power is usually turned off, and the printer is often turned on when printing is to be performed. In the conventional apparatus, after the condition as shown in FIG. 13 elapses, timer cleaning is executed when the power is turned on. For this reason, until the above-described standby time elapses after the power is turned on. Since printing cannot be started, the user is kept waiting, and there is a problem that the user is mentally bothered.
[0016]
Further, even when the printer operation power supply is continuously turned on, after the conditions as shown in FIG. 13 have passed, the timer cleaning is performed at the start of printing, and the user is similarly Had the problem of giving mental annoyance.
[0017]
From this point of view, it is desirable in terms of ease of use of the printer that the timer cleaning operation is unnecessary or that the time until the timer cleaning is required to be as long as possible to reduce the frequency of entering the cleaning operation. It is.
[0018]
Therefore, if the inventor of the present application leaves the apparatus with the nozzle opening sealed by the capping means immediately after the cleaning operation, a printing failure occurs without a cleaning operation even after leaving for a considerable period of time. It has been confirmed in the experimental results that printing can be resumed without any problem, and this is the basic concept leading to the present invention.
[0019]
It is noted that printing can be started without waiting time for the user if the cleaning is performed before the printing is finished and the operation power is turned off, or the cleaning is performed before the operation is left.
[0020]
On the other hand, if the cleaning operation is executed every time the printing operation is completed, ink consumption (dead) increases, and the user is burdened with a running cost. Similarly, when a sequence for executing the cleaning operation every time the printing operation is finished is taken, if the next printing is to be performed soon after the printing is finished, the waiting for the cleaning operation is similarly forced, which is inconvenient.
[0021]
Therefore, in order to avoid such inconvenience, when the printer is turned off, when printing is finished and no data remains in the data buffer, or when a predetermined printing time is accumulated, a certain amount or more is exceeded. The present inventors have found a means for selectively executing a cleaning operation or a flushing operation based on a combination of conditions such as when printing has not been performed over time.
[0022]
Therefore, the technical problem to be solved by the present invention is that when printing is attempted, the printing can be started immediately, and the occurrence of printing defects can be effectively suppressed. It is to provide a recording apparatus.
[0023]
Another object of the present invention is to provide an ink discharge control method in which the recording apparatus is operated according to specific conditions to realize an appropriate ink discharge operation.
[0024]
[Means for Solving the Problems]
In order to achieve the above object, a preferred embodiment of an ink jet recording apparatus according to the present invention includes: an ink jet recording head that ejects ink droplets from nozzle openings; and a nozzle opening of the recording head that is sealed. An ink jet recording apparatus equipped with a capping unit that sucks ink droplets from a nozzle opening, and measures a cumulative print time after performing a cleaning operation for sucking ink droplets from the nozzle opening of a recording head by the capping unit. Means, a discharge mode selection means for selecting an ink discharge mode in the recording head based on the time measurement data by the time measurement means, and when the next print data does not remain in the buffer after the page break of printing, the discharge Ink discharge for executing the ink discharge operation selected by the mode selection means. And a control means is provided.
[0025]
In another preferred embodiment of the ink jet recording apparatus according to the present invention, an ink jet recording head that discharges ink droplets from a nozzle opening, and the nozzle opening of the recording head is sealed and ink droplets are sucked from the nozzle opening. An ink jet recording apparatus equipped with a capping unit, wherein the capping unit counts the accumulated print time after performing a cleaning operation for sucking ink droplets from the nozzle openings of the recording head, and the timing by the timing unit An ejection mode selection means for selecting an ink ejection mode in the recording head based on the data, and an ink for executing the ink ejection operation selected by the ejection mode selection means when the power switch of the recording apparatus is turned off. And a discharge control means.
[0026]
In another preferred embodiment of the ink jet recording apparatus according to the present invention, an ink jet recording head that discharges ink droplets from a nozzle opening, and the nozzle opening of the recording head is sealed and ink droplets are sucked from the nozzle opening. An ink jet recording apparatus equipped with a capping unit, wherein the capping unit counts the accumulated print time after performing a cleaning operation for sucking ink droplets from the nozzle openings of the recording head, and the timing by the timing unit Discharge mode selection means for selecting an ink discharge mode in the recording head based on the data, and when the power switch of the recording apparatus is turned off, the discharge mode when the power switch is turned off for a predetermined time or more. An ink discharge operation selected by the selection means And a click discharge control means is provided.
[0027]
In this case, the discharge mode selection means selects a flushing mode in which the capping means ejects ink and an ink suction mode in which the nozzle opening of the recording head is sealed by the capping means to suck ink droplets. It is desirable to be configured.
[0028]
Further, it is desirable that the discharge mode selection means is configured to select a normal flushing mode in which a relatively small amount of ink is ejected and a large amount flushing mode in which a relatively large amount of ink is ejected.
[0029]
Similarly, the discharge mode selection means includes a small amount suction mode for sucking a relatively small amount of ink, a large amount suction mode for sucking a relatively large amount of ink, and an ink suction amount and a large amount suction mode in the small amount suction mode. It is desirable that the normal suction mode for executing an ink suction amount intermediate to the ink suction amount can be selected.
[0030]
In addition, an ink discharge control method for a recording head in an ink jet recording apparatus according to the present invention includes: an ink jet recording head that discharges ink droplets from a nozzle opening; and a nozzle opening of the recording head that seals the ink droplets from the nozzle opening. An ink discharge control method for a recording head in an ink jet recording apparatus equipped with a suction capping unit, which measures a cumulative print time after performing a cleaning operation for sucking ink droplets from a nozzle opening of the recording head by the capping unit. A discharge mode selection step for selecting an ink discharge mode in the recording head based on the timing data; a continuous print determination step for determining whether or not the next print data remains in the buffer after a page break of printing; In the continuous printing determination step, continuous printing is not performed. And if it is determined, it is made to perform an ink discharge step of performing an ink discharging operation which is selected by the discharge mode selection step.
[0031]
Furthermore, an ink discharge control method for a recording head in an ink jet recording apparatus according to the present invention includes: an ink jet recording head that discharges ink droplets from a nozzle opening; and the nozzle opening of the recording head is sealed and ink droplets are sucked from the nozzle opening. An ink discharge control method for a recording head in an ink jet recording apparatus equipped with a capping unit that performs a cumulative operation time after performing a cleaning operation for sucking ink droplets from the nozzle opening of the recording head by the capping unit. A discharge mode selection step for selecting an ink discharge mode in the recording head based on the timing data, a switch-off determination step for determining whether a power switch of the recording apparatus is turned off, and the switch-off determination step. , Turn on the power of the recorder. There When it is determined to have been turned off, in some cases made the to perform the ink ejection step of performing an ink discharging operation which is selected by the discharge mode selection step.
[0032]
Furthermore, an ink discharge control method for a recording head in an ink jet recording apparatus according to the present invention includes an ink jet recording head that discharges ink droplets from a nozzle opening, and a nozzle opening of the recording head that seals the ink droplets from the nozzle opening. An ink discharge control method for a recording head in an ink jet recording apparatus equipped with a capping means for sucking ink, wherein the accumulated print time after performing a cleaning operation for sucking ink droplets from the nozzle openings of the recording head by the capping means is calculated. The time when the discharge mode selection step of selecting the ink discharge mode in the recording head based on the time measurement data and the power switch of the recording apparatus is turned off continues the power switch OFF state for a predetermined time or more. Power off state judgment And an ink discharge step for performing the ink discharge operation selected in the discharge mode selection step when it is determined in the power-off state determination step that the OFF state of the power switch has continued for a predetermined time or more. It may be made like this.
[0033]
Even when any of these ink discharge control methods is executed, it is desirable to immediately shift to the capping step of sealing the nozzle openings of the recording head by the capping means after the ink discharging step.
[0034]
In any of the ink discharge control methods, preferably, in the discharge mode selection step, a process table corresponding to an elapsed time after the previous cleaning operation is performed is referred to or calculated, and ink is supplied to the capping unit. The ink discharge operation is selected in either a flushing mode in which the ink is discharged or an ink suction mode in which the nozzle opening of the recording head is sealed by a capping unit to suck an ink droplet.
[0035]
More preferably, in the discharge mode selection step, a normal flushing mode in which a relatively small amount of ink is ejected by referring to or calculating a processing table and a large amount of flushing mode in which a relatively large amount of ink is ejected are changed to the previous time. The selection is made in accordance with the elapsed time after performing the cleaning operation, and the processing table is referred to or calculated in the same manner, and a small amount suction mode for sucking a relatively small amount of ink, and a relatively large amount of ink After the previous cleaning operation, the large-scale suction mode for sucking the ink and the normal suction mode for executing the ink suction amount intermediate between the ink suction amount in the small-volume suction mode and the ink suction amount in the large-volume suction mode. Selection is made according to time.
[0036]
According to the ink jet recording apparatus configured as described above and the ink discharge control method of the recording head in the apparatus, the print accumulated time after the cleaning operation is performed by the time measuring means is counted, and the discharge mode is based on the time measured data. The ink discharging mode in the recording head is selected by the selecting means. The ink discharge control means controls to execute the ink discharge mode selected by the discharge mode selection means when the next print data does not remain in the buffer after the page break of printing.
[0037]
Similarly, when the power switch is turned off, the ink discharge mode selected by the discharge mode selection unit is controlled based on the time accumulation data of the print accumulated time.
[0038]
Further, similarly, when the power switch of the recording apparatus is turned off, when the duration time of the power switch in the off state becomes a predetermined time or more, it is selected by the discharge mode selecting means based on the time measurement data of the accumulated print time. It is also controlled to execute the ink discharge mode.
[0039]
By carrying out such control, when the user tries to start printing or when the power is turned on, the process of discharging ink from the recording head has already been completed, and normal printing is possible. Therefore, it is possible to immediately shift to a printing operation. Therefore, it is possible to eliminate the inconvenience of forcing the user to wait for printing by executing the timer cleaning.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus that employs an ink discharge control method according to the present invention will be described based on embodiments 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.
[0041]
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.
[0042]
Reference numeral 11 in the figure denotes a capping device as a capping means arranged outside the non-printing area, and a black head cap unit 37 and a color head cap unit 38 are arranged. A suction pump 12 for applying a negative pressure to the capping device 11 is disposed below the capping device 11.
[0043]
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.
[0044]
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.
[0045]
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.
[0046]
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.
[0047]
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.
[0048]
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.
[0049]
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.
[0050]
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. Further, each of the cap units 37 and 38 is provided with an air release port 19 to be described later on the lower bottom thereof, and the other ends of the tubes 27 having one end connected to the air release port 19 are connected to the valve unit 28, respectively. Has been.
[0051]
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.
[0052]
FIG. 4 shows the color head cap unit 38 as viewed from above, and FIG. 5 shows a cross-sectional view of the color recording head 8 capped by the cap unit 38. The cap unit 38 shown in FIG. 5 is shown in a cross-sectional view along the line AA in FIG.
[0053]
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. .
[0054]
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.
[0055]
At the lower bottom portion of the cap case 40, an air opening 19 for opening the inside of the cap member 16 to the atmosphere is provided through the cap member 16. The air opening 19 is connected to the valve unit 28 via the tube 27 as described above.
[0056]
An ink suction port 18 is formed in the lower bottom portion of the cap case 40 so as to pass through the cap member so as to be adjacent to the atmosphere opening port 19, and the ink suction port 18 is connected to the ink suction port 18 via a tube (not shown). As described above, the suction pump 12 is connected.
[0057]
Next, FIG. 6 shows an example of a control circuit mounted on the recording apparatus having the above-described configuration. In FIG. 6, the recording heads 7 and 8, the ink cartridges 9 and 10, and the valve unit 28 (however, in FIG. 6, the two valve units are shown as 28A and 28B) are indicated by the same reference numerals. Therefore, the description thereof is omitted.
[0058]
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 driving unit 51 is configured to receive a flushing command signal from the flushing control unit 52 and output a driving signal for the flushing operation to the recording heads 7 and 8 in addition to the driving signal based on the print data. Yes.
[0059]
Reference numeral 53 denotes a cleaning control means, which controls the pump drive means 56 by a control signal from a cleaning (hereinafter also referred to as CL) command detection means 54 or a discharge mode selection means 55 to control the suction pumps 12A and 12B. To do.
[0060]
The print control unit 50 supplies a control output when printing is performed to the print accumulation time detection unit 57, and the cleaning control unit 53 also resets the print accumulation time detection unit 57. A signal is supplied. As a result, the print accumulated time detecting means 57 acts to reset the accumulated time to zero by the reset signal from the cleaning control means 53 and to count up the print accumulated time by the control output from the print control means 50. That is, the print accumulated time detecting unit 57 functions as a time measuring unit that measures the accumulated print time after the cleaning operation is performed.
[0061]
The count-up output (timed output) by the accumulated print time detection means 57 is configured to be supplied to the discharge mode selection means 55. The discharge mode selection unit 55 has a function of selecting an ink discharge mode with reference to an ink discharge processing table (to be described later) built in the ROM 58 based on the count-up output from the accumulated print time detection unit 57.
[0062]
The discharge mode selection means 55 can send a control signal to the flushing control means 52 constituting one of the ink discharge control means or the cleaning control means 53 constituting the other one of the ink discharge control means. The flushing control or the cleaning control is executed based on the ink discharge mode selected by the discharge mode selection means 55.
[0063]
On the other hand, the print control unit 50 is configured to supply print data to the print data detection unit 59. That is, the print data detection means 59 detects whether or not the next print data remains in the buffer after the page break of printing. The control output from the print data detection means 59 is sent to the discharge mode selection means 55. It is configured to be supplied.
[0064]
Further, the host computer of the recording apparatus is configured to supply the power switch status to the power status detection means 60. That is, the power state detection means 60 is configured to detect whether or not the power switch is turned off and to supply a control signal based on the power switch to the discharge mode selection means 55.
[0065]
A timer 61 is connected to the power state detection means 60, and this timer 61 counts up the elapsed time after the power switch of the apparatus is turned off. As a result, a control signal is supplied from the power supply state detection means 60 to the discharge mode selection means 55 after a predetermined time (T3), which will be described later, has elapsed, that is, when the power supply switch is turned off for a predetermined time or longer. It is also configured to do.
[0066]
Reference numeral 62 in FIG. 6 denotes a cleaning command switch provided on the control panel of the case. When the user pushes this on to clear the clogging of the recording head, the CL command detection means 54 Is configured to perform a cleaning operation.
[0067]
Next, the operation of the ink discharge control operation of the recording apparatus configured as described above will be described based on the control flows shown in FIG. 7, FIG. 10, and FIG. First, FIG. 7 shows an ink discharge control sequence executed at the end of printing of one unit.
[0068]
When paper discharge is performed upon completion of printing of one unit, in step S11, the print data detection unit 59 fetches status data from the print control unit 50 and determines whether there is print data for the next page. If it is determined in step S11 that there is a next print page (data) (Yes), printing is continued. If it is determined that there is no next print page (in the case of No), the process proceeds to step S12 and waits for a predetermined time (T1).
[0069]
This time T1 is set to about several seconds, for example. Within a few seconds set as T1, the determination is made whether or not there is a next page by circulating between step S1 and step S2. If it is determined that there is a next page during this period, As described above, the printing operation is continued.
[0070]
The reason why the predetermined waiting time T1 is provided is that, in general, in the case of multi-page printing, the data of the next page exists in the printer buffer after the page break, so there is no waiting time (that is, 0). Immediately in seconds, it can be determined whether there is a next page. However, the operation of the host computer may be slow, and a waiting time T1 of several seconds is set assuming such a case.
[0071]
If it is determined in step S12 that the predetermined time (T1) has elapsed, the process proceeds to step S13, where it is determined whether the accumulated print time from the previous cleaning is longer than T2. Then, the ink discharge process shown in step S14 or step S15 is determined according to T2.
[0072]
The accumulated print time T2 is timed by the accumulated print time detecting means 57 shown in FIG. 6, and this time-measured data is supplied to the discharge mode selecting means 55. The discharge mode selection means 55 selects an ink discharge process mode based on a table shown in FIG.
[0073]
As shown in FIG. 8, when the cumulative print time T2 from the previous cleaning is 10 minutes or less, the normal flushing mode (first flushing mode) with an ink discharge amount of 0.01 g is selected. If the accumulated print time T2 from the previous cleaning is between 10 minutes and 30 minutes, the large flushing mode (second flushing mode) with an ink discharge amount of 0.05 g is selected, and the T2 starts from 30 minutes. When it is within 1 hour, the small amount suction mode (first suction mode) in which about 0.1 g of ink is sucked from the recording head by the capping device is selected, and when T2 is between 1 hour and 3 hours The normal suction mode (second suction mode) in which about 0.15 g of ink is sucked from the recording head by the capping device is selected, and when T2 exceeds 3 hours, the ink is sucked from the recording head by the capping device. A large-volume suction mode (third suction mode) for sucking about 0.2 g is selected.
[0074]
In the flowchart shown in FIG. 7, the first flushing mode is executed in step S15, and the second flushing mode and the first to third suction modes are shown executed in step S14. For convenience of explanation, there is no particular meaning here. In short, it means that each of the ink discharge modes described above is executed in step S14 or step S15.
[0075]
When the first or second flushing mode is selected, a flushing control command is output to the flushing control means 52 from the discharge mode selection means 55 shown in FIG. In response to this, the flushing control means 52 sends a so-called idle ejection signal corresponding to the first or second flushing mode to the head driving means 51 to control the ejection amount (0.01 g or 0.05 g). It is made like.
[0076]
On the other hand, when the first to third suction modes are selected, a cleaning control command is output to the cleaning control unit 53 from the discharge mode selection unit 55 shown in FIG. In response to this, the cleaning control means 53 sends a control signal corresponding to one of the first to third suction modes to the pump drive means 56, and the amount of suction (0.1g, 0.15g) from the nozzle opening by the capping device. , 0.2 g).
[0077]
As described above, when the flushing process or the ink suction process is performed in step S14 or step S15, the recording head is capped by the capping device in step S16. Thus, the nozzle opening is prevented from being dried by the capping device during the rest period of the recording apparatus, and the next print data is awaited.
[0078]
In the control sequence shown in FIG. 7, it is detected that there is no next print data, a flushing process or an ink suction process is executed between them, and the next printing is in a standby state. When printing is to be performed, printing can be started immediately.
[0079]
In step S13 in the control sequence shown in FIG. 7, the ink discharge process mode is selected with reference to the process table shown in FIG. 8, but for example, the corresponding process as shown in FIG. Can also be performed.
[0080]
That is, the horizontal axis in FIG. 9 indicates the accumulated print time (T2) from the previous cleaning process, and the vertical axis indicates the amount of ink to be discharged. A broken line indicates an ink discharge mode by flushing, and a solid line indicates an ink discharge mode by suction.
[0081]
As can be understood from the relationship shown in FIG. 9, the selection of the ink discharge mode and the ink discharge amount can be obtained by a logical operation using the print accumulated time (T2) from the previous cleaning process as a parameter. In addition, since the ink discharge amount can be set in a relationship substantially proportional to the parameter, it is possible to execute an efficient process that can reduce the ink discharge amount.
[0082]
Next, FIG. 10 shows an ink discharge control sequence executed when the power switch of the apparatus is turned off.
[0083]
When the power switch of the apparatus is turned off, it can be detected by the power supply state detection means 60 in FIG. 6, and a command signal is provided from the detection means 60 to the discharge mode selection means.
[0084]
When the power supply state detecting means 60 detects that the power switch is turned off, the routine of step S21 in FIG. 10 is entered. Step S21 is the same as Step S13 shown in FIG. 7, and Steps S22 to S24 are also the same as Steps S14 to S16 shown in FIG. Therefore, the description is omitted.
[0085]
In short, when the power switch of the apparatus is turned off, a flushing process or an ink suction process similar to that described with reference to FIG. 7 is performed, and the main power supply of the apparatus is shut off with the print head printing function restored. The Therefore, by executing the processing shown in FIG. 10, when the user next turns on the power, the printing operation can be started immediately.
[0086]
Next, FIG. 11 shows that when the power switch of the apparatus is turned off and the time of the off state reaches a predetermined time, that is, when the leaving time exceeds a predetermined time, the flushing process or the ink suction process is automatically executed. Thus, the printing function of the recording head is restored.
[0087]
When the power switch of the apparatus is turned off, this can be detected by the power state detection means 60 in FIG. And the timer 61 connected to the power supply state detection means 60 counts up elapsed time after a power switch is turned off. In step S31 in FIG. 11, after a predetermined time (T3) has elapsed, that is, when the state where the power switch is turned off has passed for a predetermined time (T3) or longer, the process proceeds to step S31, where Is made.
[0088]
Then, the flow proceeds to the flow from step S33 to step S36, which is the same as the flow from step S13 to step S16 described with reference to FIG. 7, and therefore the description thereof is omitted.
[0089]
When the power switch of the apparatus is turned off and left for a long time, even if the nozzle plate of the recording head is capped by the capping apparatus, the recording head may cause a printing failure due to the increased viscosity of the ink.
[0090]
Therefore, as described above, when the predetermined time (T3) elapses, the flushing process or the ink suction process similar to the case described with reference to FIG. 7 is executed, and the printing function of the recording head is restored. The main power is turned off. As described above, by executing the processing shown in FIG. 11, when the user next turns on the power, the printing operation can be started immediately.
[0091]
The timer 61 shown in FIG. 6 is reset when the print function recovery process is executed by the flushing process or the ink suction process, and when the predetermined time (T3) has elapsed, the above-described process is executed again. To be made.
[0092]
FIG. 12 shows ink discharge conditions performed when the power is turned on or when printing is started in the apparatus provided with the processing sequence according to the present invention shown in FIG. 7 or FIG. This is a comparison with the conventional apparatus shown.
[0093]
In the case where the processing sequence according to the present invention shown in FIG. 7 or FIG. 10 is carried out, as shown in FIG. 12, when the elapsed time from the previous cleaning is 50 hours or less, only the flushing operation is performed. Printing can be started.
[0094]
Also, it is necessary to perform the ink suction operation only when the elapsed time from the previous cleaning has passed 50 hours or more. Therefore, compared with the processing required in the conventional apparatus shown in FIG. 13, by applying the present invention, the frequency of occurrence of the cleaning processing performed when the power is turned on or when printing is started can be greatly reduced.
[0095]
【The invention's effect】
As is apparent from the above description, according to the ink jet recording apparatus and the ink discharge control method of the recording head in the apparatus, the cleaning operation for sucking ink droplets from the nozzle opening of the recording head was performed by the capping means. There is basically provided a time measuring means for measuring the accumulated time for the subsequent printing, and a discharge mode selecting means for selecting the ink discharge mode in the recording head based on the time measurement data by the time measuring means. In the case where no print data remains in the buffer or when the power switch of the apparatus is turned off, the ink discharge operation selected by the discharge mode selection means is executed.
[0096]
Similarly, when the power switch of the apparatus is turned off, the ink discharge operation selected by the discharge mode selection means is executed when the power switch remains off for a predetermined time or longer.
[0097]
Therefore, by performing such control, when the user tries to start printing or when the power is turned on, the ink discharge process from the recording head has already been completed, and the normal printable state is obtained. Since it has been made, it is possible to immediately shift to a printing operation.
[0098]
Alternatively, the frequency with which cleaning must be performed when the user tries to start printing or when the power is turned on can be greatly reduced.
[0099]
Accordingly, it is possible to greatly reduce the inconvenience of forcing the user to wait for printing by executing cleaning when printing is started or when the power is turned on, or the frequency of occurrence of the inconvenience.
[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.
FIG. 4 is a top view of a cap unit mounted on the recording apparatus of the present invention.
5 is a cross-sectional view showing a state where the cap unit shown in FIG. 4 is cut along line AA and capped on a recording head. 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 illustrating a first control sequence example of ink discharge processing performed in the recording apparatus of the present invention.
FIG. 8 is a schematic diagram showing an example of a processing table constructed in the ROM shown in FIG. 6;
FIG. 9 is a schematic diagram showing a function of calculation processing in place of the processing table shown in FIG. 8;
FIG. 10 is a flowchart illustrating a second control sequence example of ink discharge processing performed in the recording apparatus of the present invention.
FIG. 11 is a flowchart illustrating a third control sequence example of ink discharge processing performed in the recording apparatus of the present invention.
FIG. 12 is a schematic diagram showing ink discharge conditions performed when power is turned on or when printing is started when the present invention is applied.
FIG. 13 is a schematic diagram showing ink discharge conditions performed when power is turned on or when printing is started in a conventional apparatus.
[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 Flushing control means
53 Cleaning control means
55 Discharge mode selection means
56 Pump drive means
57 Accumulated print time detection means
58 ROM
59 Print data detection means
60 Power supply state detection means
61 timer

Claims (6)

An ink jet recording apparatus equipped with an ink jet recording head that discharges ink droplets from a nozzle opening, and a capping unit that seals the nozzle openings of the recording head and sucks ink droplets from the nozzle openings,
Clocking means for timing the cumulative printing time after performing a cleaning operation for sucking ink droplets from the nozzle openings of the recording head by the capping means;
A discharge mode selection means for selecting an ink discharge mode in the recording head based on time measurement data by the time measurement means;
Ink discharge control means for executing the ink discharge operation selected by the discharge mode selection means;
Print data detection means for detecting whether or not the next print data remains in the buffer after a page break of printing, and supplying the detection result to the discharge mode selection means,
When the print data detection means supplies a control output indicating that the next print data does not remain in the buffer after a page break of printing to the discharge mode selection means, the discharge mode selection means selects an ink discharge mode, and An ink discharge operation based on the selected ink discharge mode is always executed.
An ink jet recording apparatus. The power supply state detection unit according to claim 1, further comprising: a power supply state detection unit that detects whether or not a power switch of the ink jet recording apparatus is turned off and supplies a control signal based on the power switch to the discharge mode selection unit
When the power switch of the ink jet recording apparatus is turned off, the discharge mode selecting means selects an ink discharge mode, and an ink discharge operation based on the selected ink discharge mode is executed. ,
An ink jet recording apparatus. The flushing mode for ejecting ink to the capping unit by the discharging mode selection unit and the ink suction mode for sucking ink droplets by sealing the nozzle openings of the recording head by the capping unit are selected. The ink jet recording apparatus according to claim 1 , wherein the ink jet recording apparatus is provided. The discharge mode selecting means, according to claim 3, characterized in that it is constituted further a normal flushing mode for discharging a relatively small amount of ink, so that the mass flushing mode for discharging a relatively large amount of ink can be selected 2. An ink jet recording apparatus according to 1. The discharge mode selection means further includes a small amount suction mode for sucking a relatively small amount of ink, a large amount suction mode for sucking a relatively large amount of ink, an ink suction amount by the small amount suction mode, and an ink suction amount by the large amount suction mode. The ink jet recording apparatus according to claim 3 , wherein the ink jet recording apparatus is configured to select a normal suction mode in which an intermediate ink suction amount is executed. An ink jet recording head that ejects ink droplets from a nozzle opening;
Capping means for sealing the nozzle opening of the recording head and sucking ink droplets from the nozzle opening;
Clocking means for timing the cumulative printing time after performing a cleaning operation for sucking ink droplets from the nozzle openings of the recording head by the capping means;
A discharge mode selection means for selecting an ink discharge mode in the recording head based on time measurement data by the time measurement means;
An ink discharge control means for executing an ink discharge operation selected by the discharge mode selection means, and an ink discharge control method for a recording head in an ink jet recording apparatus,
It is determined whether or not the next print data remains in the buffer after the page break of printing, and a continuous print determination step for supplying the determination result to the discharge mode selection unit is executed.
In the continuous printing determination step, when it is determined that there is no continuous printing,
A discharge mode selection step of selecting an ink discharge mode in the recording head based on time measurement data by the time measuring means;
An ink discharge step for performing an ink discharge operation based on the ink discharge mode selected in the discharge mode selection step;
The ink discharge control method from the recording head in the ink jet recording apparatus, wherein

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