JP3978923B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an ink jet recording apparatus that performs recording by ejecting ink droplets onto a recording medium, and sucks and discards ink containing air bubbles or ink that is being dried from the nozzles of the recording head. The present invention relates to an ink jet recording apparatus having a purging function for recovering the ink discharge function of a nozzle to a good state.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an inkjet recording apparatus, there is provided a purging apparatus that covers a nozzle cap surface of a recording head with a suction cap and sucks and discharges defective ink from the nozzle by using a pump to create a negative pressure. Is known.
[0003]
[Problems to be solved by the invention]
By the way, in a multicolor recording apparatus, different inks are stored in ink cartridges connected to a plurality of recording heads, and each ink has a drying property, foaming property, defoaming property, wettability, surface tension, The physical properties such as viscosity are different. For this reason, when the ink cartridge connected to the recording head is replaced, air enters the ink supply path connecting the ink cartridge and the recording head, and the air enters the ink in the ink supply path, generating bubbles. However, the degree depends on each ink. The bubbles in the ink grow greatly with the passage of time, but the degree varies depending on each ink. In addition, gas is generated after passing through an adhesive between members constituting the manifold that forms the ink supply path, and the gas becomes bubbles in the ink, but the degree varies depending on each ink.
Then, as the bubbles grow larger and the number of bubbles increases, the bubbles cannot be discarded unless a large amount of ink is sucked.
[0004]
Moreover, when the ink jet recording apparatus is not used, the nozzle opening surface of the recording head is covered with a capping device to prevent the ink from drying, but in reality, the drying gradually progresses over time. Also depends on the ink.
[0005]
However, in the above-described conventional apparatus, the purging device always performs a suction operation under a constant condition regardless of the types of inks of a plurality of recording heads provided. Depending on the suction operation, bubbles or dry ink in the ink may be discarded. It may not be possible to get out.
[0006]
In other words, in the above-described conventional apparatus, there are cases where the nozzle ejection function may not be recovered depending on the suction operation under certain conditions, and if the purging conditions are set safely, ink may be sucked wastefully. There is a problem.
[0007]
Therefore, in order to solve the above problem, the present invention uses a suction condition optimized for a plurality of recording heads provided for each type of ink, thereby improving recording quality and eliminating unnecessary suction of ink. An object of the present invention is to realize an ink jet recording apparatus that can perform the above-described process.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, ink stored in a replaceable ink cartridge is ejected from a nozzle communicating with the ink cartridge to a recording medium for each type of ink to be recorded. Multiple recording heads and the nozzles of this recording head Rai In an ink jet recording apparatus provided with an ink suction unit that sucks ink and makes the ink discharge state good. The plurality of recording heads include one recording head connected to an ink cartridge containing one ink, and another recording head connected to an ink cartridge containing another ink that is more likely to foam than the one ink. And a timer for measuring the time from when the ink suction means performs the ink suction operation until the recording data is input, and when the ink suction means receives the recording data Detects the time measured by the timer, and the longer the detection time, the more ink is sucked, and the suction amount corresponding to the detection time is set to the other recording head than from the one recording head. The system operates in such a way that the number of people from the source increases, and when no recording data is input, it receives a suction operation command from the user. In this case, the suction amount from the one recording head and the suction amount from the other recording head are equal to each other, and these suction amounts are the minimum suction amount of the suction operation performed when recording data is input. Works to be equal to Adopt technical means of being.
[0009]
[0010]
[0011]
[0012]
In the invention according to claim 2, in the ink jet recording apparatus according to claim 1, The ink suction means is configured such that when the ink cartridge is replaced when recording data is not input, the suction amount from the other recording head is larger than the suction amount from the one recording head, and The suction amount operates to be larger than the maximum suction amount of the suction operation performed when the recording data is input. Adopt technical means of being.
[0013]
[0014]
[0015]
[0016]
In the invention according to claim 3, claim 1 is provided. Or 2 In the inkjet recording apparatus described in The ink suction means increases the suction amount by increasing the number of times of suction. Adopt technical means of being.
[0017]
[0018]
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an ink jet recording apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0020]
FIG. 1 is an explanatory view showing a part of the internal structure of an ink jet recording apparatus (hereinafter abbreviated as a recording apparatus).
[0021]
The recording apparatus 10 includes a medium conveying unit that conveys a recording sheet 11 as a recording medium by the rotation of a roller 12. In front of the roller 12, guide bars 13 and 13 are provided in parallel with the axis of the roller 12, and a carriage 29 on which the recording head unit 20 is mounted is slidably supported on the guide bars 13 and 13. Has been. The carriage 29 is connected to an endless belt 17 stretched around pulleys 15 and 16, and is moved in parallel with the recording paper 11 by the rotation of the carriage motor 14 connected to the pulley 15.
[0022]
The recording head unit 20 includes a black recording head 21 that discharges black ink, a yellow recording head 22 that discharges yellow ink, a cyan recording head 23 that discharges cyan ink, and a magenta ink that discharges magenta ink. And a recording head 24. Ink cartridges 25 to 28 as ink supply sources for supplying ink to the recording heads are detachably connected to the recording heads 21 to 24, respectively.
[0023]
Each of the recording heads 21 to 24 is provided with a plurality of ink chambers (not shown) that store inks respectively supplied from the ink cartridges 25 to 28, and each ink chamber has a surface facing the roller 12. A nozzle (not shown) for discharging ink in the ink chamber is opened. The ink in each ink chamber is ejected as droplets from the nozzle by the pressure at the time of boiling by deformation of the piezoelectric element or local heating by the heater, and recording is performed on the recording paper 11.
[0024]
At a predetermined position on the left side of the roller 12 that is outside the recording range with respect to the recording paper 11, an ink absorbing pad 30 made of a porous material, which is a waste ink storage portion, is provided, and flushing that each recording head 21 to 24 performs preliminary ejection. Ink is ejected from the recording heads 21 to 24 when the ink absorbing pad 30 is stored. The flushing is performed before the recording head unit 20 performs recording and periodically during the recording operation. By this flushing, the nozzles of the recording heads 21 to 24 are prevented from being dried, and ink ejection failure due to the drying is prevented. .
[0025]
Further, on the right side of the roller 12 outside the recording range, a purging device 40 that recovers non-ejection or ejection failure of each recording head 21 to 24 is disposed. The purging device 40 is provided with a suction cap 41 that is alternatively placed over the nozzle opening surfaces of the recording heads 21 to 24. The suction cap 41 should perform purging of the recording heads 21 to 24. When the recording head reaches a purging position opposite to the suction cap 41, the recording head advances toward the recording head by the rotation of a cam 42 driven by a driving device (not shown) and covers the nozzle opening surface of the recording head. Then, the pump 43 is driven, and the negative pressure generated by the pump 43 sucks ink from the nozzle of the recording head covered with the suction cap 41, thereby restoring the ejection function of the recording head to a good state. With one rotation of the cam 42, a series of operations of capping the nozzle opening surface by the suction cap 41, driving the pump 43, and detaching the suction cap 41 from the nozzle opening surface are performed once.
As will be described later, this operation is performed once or a plurality of times.
[0026]
A wiper member 50 is provided between the suction cap 41 and the roller 12. The wiper member 50 advances into the moving path of the recording head at the timing when the purging of each recording head is completed by the rotation of the cam 42, and wipes the nozzle opening surface of the recording head that moves to the recording area by the carriage. As a result, ink or foreign matter adhering to the nozzle opening surface of the purged recording head is wiped off, and the recording surface of the recording paper 11 is prevented from being stained with excess ink.
[0027]
On the opposite side of the suction cap 41 from the recording area, there is provided a capping device 60 that covers the nozzle opening surfaces of the recording heads 21 to 24 of the recording head unit 20 with a plurality of caps 61 that correspond one-to-one. Yes. When the recording head unit 20 returns to the home position, the cap 61 moves forward toward the recording head in conjunction with the movement of the carriage by the action of a cam member (not shown) and covers the nozzle opening surface of the recording head. As a result, the ink of the recording heads 21 to 24 is prevented from being dried while the recording apparatus 10 is not used.
[0028]
Next, the configuration of the main control system of the recording apparatus 10 will be described with reference to FIGS.
[0029]
FIG. 2 is a block diagram showing a main control system of the recording apparatus 10, and FIG. 3 is an explanatory diagram of a purging table stored in the ROM of the recording apparatus 10.
[0030]
As illustrated in FIG. 2, the recording apparatus 10 includes a known microcomputer 70 having a single-chip configuration, a ROM 74, and a RAM 75. The microcomputer 70 includes an operation panel 81 for a user to give a recording instruction, a motor drive circuit 78 for driving the carriage motor 14, a motor drive circuit 79 for driving a drive motor 84 for the roller 12, A motor drive circuit 77 for driving the drive motor 76 of the purge device 40, a sensor 88 for detecting the presence or absence of the ink cartridges 25 to 28, and the like are connected. A sensor 88 is provided for each ink cartridge, and can determine which ink cartridge has been replaced.
[0031]
The recording heads 21 to 24 are driven by a drive circuit 83, and the drive circuit 83 is controlled by a control circuit 73. The drive circuit 83 generates a drive signal suitable for the recording head based on the control of the control circuit 73.
[0032]
The microcomputer 70 is connected to the ROM 74, the RAM 75, and the control circuit 73 via an address bus AB and a data bus DB. The microcomputer 70 generates a recording timing signal TS and a control signal RS according to a program stored in advance in the ROM 74 and transfers the recording timing signal TS and the control signal RS to the control circuit 73.
[0033]
The control circuit 73 includes a gate array, and is recording data for forming the recording data on a recording sheet based on the recording data stored in the image memory 82 in accordance with the recording timing signal TS and the control signal RS. The transfer data DATA, the transfer clock TCK, the strobe signal STB, and the recording clock ICK that are synchronized with the transfer data DATA are generated, and the signals DATA, TCK, STB, and ICK are transferred to the drive circuit 83. The control circuit 73 also causes the image memory 82 to store recording data transferred from an external device such as the personal computer 71 via the Centronics interface 72. The control circuit 73 generates a Centronics data reception interrupt signal WS based on the Centronics data transferred from the personal computer 71 or the like via the Centronics interface 27, and transfers the signal WS to the microcomputer 70. To do. The signals DATA, TCK, STB, and ICK are transferred via a harness cable that connects the control circuit 73 of the recording apparatus main body and the drive circuit 83 on the carriage 29.
[0034]
In order to execute purging control, which will be described later, the ROM 74 stores the purging tables 90 and 91 shown in FIGS. A timer T that measures the time from when the purging device 40 performs parsing to when a recording operation command is issued to the recording head is constituted by a CPU 70, a ROM 74, and a RAM 75 (shown as a timer T in the CPU 70 in the drawing). ).
[0035]
Here, the contents stored in the purging tables 90 and 91 will be described. In the figure, initial purging is an operation for introducing new ink to the recording head by suction when the ink cartridge is replaced. Further, the normal purge is an operation for purging by arbitrarily operating the purge key of the operation panel 81 when the user determines that there is an ink ejection failure by looking at the recording result.
[0036]
The purging table 90 shows the contents when purging the black recording head 21 which is easily foamed and easily dried. As shown in FIG. 3A, in the purging table 90, the number of times the pump 43 is driven when the initial purging of the black recording head 21 is executed, that is, the number of purgings is set to six. Further, the parsing when the time T until the CPU 70 detects that the recording data as the recording operation command is input from the personal computer 71 after the previous purging is performed is more than 3 days and less than 6 days. The number of times of purging is set to once, the number of purging when the time T is longer than 6 days and less than 9 days is set to 2, and the number of purging when the time T is longer than 9 days is set to 3 times. Yes. The number of purgings for normal purging is set to one.
[0037]
Further, the purging table 91 is referred to by the CPU 70 when the color recording heads 22 to 24 which are hard to foam and are difficult to dry perform purging. As shown in FIG. 3B, in the purging table 91, when the initial purging of the color recording heads 22 to 24 is executed, the number of times the pump 43 is driven, that is, the number of purgings is set to five. . In addition, the parsing when the time T until the CPU 70 detects that the recording data as the recording operation command is input from the personal computer 71 after the previous purging is performed is more than 5 days but not more than 10 days. The number of purgings is set to once, the number of purgings when the time T exceeds 10 days and 15 days or less is set to 2, and the number of purgings when the time T exceeds 15 days is set to 3 times. Yes. The number of purgings for normal purging is set to one.
[0038]
As described above, the number of purging operations in the initial purging is the largest because the new ink must be introduced to the recording head when the ink cartridge is replaced, and the part where the ink cartridge and the recording head are connected at the time of replacement. Since air enters and the air is taken into the ink in the ink supply path between the ink cartridge and the recording head and becomes a large number of bubbles, other timing is required to discard the ink containing these bubbles. This is because it is necessary to suck more ink than at the time of purging performed in the above. The reason why the number of initial purgings of the black recording head 21 is larger than the number of initial purgings of the color recording heads 22 to 24 is that the black ink tends to foam more than the color ink.
[0039]
In addition, the period for performing purging according to the time from when the previous purging is performed until the recording data is input is shorter in the black recording head 21 than in the color recording heads 22 to 24. . This is because, as described above, there are more bubbles generated by initial purging in black ink than in color ink, and the generated bubbles may remain in the ink. This is because the grown bubbles are quickly discarded before they grow to the extent of causing non-ejection. In addition, the black ink is easier to dry than the color ink, so that purging must be performed earlier.
[0040]
Next, the control executed by the CPU 70 for performing purging will be described with reference to the flowchart of FIG. 4 showing the control contents.
[0041]
Note that the timer T counts the elapsed time since the previous purging.
[0042]
First, the purging control for initial purging will be described.
[0043]
First, when a purge command is issued (Yes in step 101), it is determined whether the purge command is for executing purging associated with ink cartridge replacement, that is, initial purging, or the user has operated the purge key. (Step 103). This initial purging is determined based on the detection result that the ink cartridge sensor 88 is turned on or off, or the property of the so-called printer driver for driving the recording device installed in the storage device of the personal computer 71 by the user. This is performed based on whether or not a parsing instruction is issued.
[0044]
When it is determined that the purge command is for executing the initial purging (Yes in Step 103), the type of the print head that has been purged is determined (Step 106). This determination is made based on the detection result of which one of the plurality of ink cartridge sensors 88 is operated, or on which print head is instructed for parsing in the printer driver properties. .
[0045]
If it is determined that the command is a purge command for the black recording head (Yes in step 106), the number of purging times indicating the number of purgings of six times is read from the purging table 90 stored in the ROM 74. Subsequently, the black recording head 21 is moved to a purging position opposite to the suction cap 41, the suction cap 41 is placed on the nozzle opening surface of the black recording head, and the cam 42 is driven six times to perform purging six times. Initial purging is executed (step 107). If it is determined that the purge command is for the color recording head (No in Step 106), the purging frequency data indicating the number of purgings of 5 times is read from the purging table 91, and the cam 42 is driven 5 times to 5 The parsing is performed in the same manner as described above (step 108). Subsequently, the timer T is reset (step 200), and the count of the timer T is started again (step 210).
[0046]
In this way, by performing initial purging, new ink is introduced into the recording head, and when the ink cartridge is replaced, ink containing bubbles generated in the ink in the ink supply path is sucked and discarded. can do.
[0047]
If the purging is not accompanied by the replacement of the ink cartridge, for example, if the user operates the purging key, or if purging is specified in the printer driver installed in the personal computer 71 (Yes in step 104). Then, the parsing frequency data indicating the number of times of one parsing is read from the parsing table 90, and one normal parsing is executed (step 105). When no recording data is input and a signal that is not a purge command is input (No in step 101), the corresponding process is executed (step 102).
[0048]
Next, purging control in cases other than the initial purging will be described.
[0049]
When recording data is input from the personal computer 71 (Yes in step 100), the count value of the timer T is detected (step 110), and the type of the recording head is determined (step 120). Here, if it is determined that the recording head is for black (Yes in Step 120), it is determined whether the detected count value of the timer T exceeds 3 days (Step 121) and does not exceed 3 days. In the case (No in Step 121), the recording data input from the personal computer 71 is recorded without performing purging (Step 190).
[0050]
In other words, in the case of the black recording head, if it does not exceed 3 days since the previous purging, even if bubbles are generated in the ink supply path, the bubble growth is estimated to be small. Also, since the ink has not been dried, recording is performed as it is while preventing unnecessary suction of the ink.
[0051]
In addition, when it is more than 3 days and less than 6 days since the previous purging was executed (No in step 122), the purging frequency data indicating the number of times of one purging is read from the purging table 90, and the pump 43 is turned on. One-time purging is executed by driving once. Further, when the past parsing is performed and the period is more than 6 days but not more than 9 days (No in step 123), the parsing frequency data indicating the number of times of parsing is read from the parsing table 90 and read twice. When purging is executed (step 170) and more than nine days have passed since the previous parsing was executed (Yes in step 123), the parsing frequency data indicating the number of times of parsing is read from the parsing table 90 and read three times. Is performed (step 180).
[0052]
When the purging is completed, the timer T is reset (step 200), and the timer T starts counting again (step 210). Then, according to the input recording data (Yes in Step 100), recording is performed (Step 190).
[0053]
Thus, the longer the time elapsed since the previous purging was executed, the more the number of purgings is executed. In other words, the longer the elapsed time from the previous purging, the larger the bubbles in the ink in the ink supply path, or it is estimated that many bubbles are generated, and the drying of the ink also proceeds Not sucking a lot of ink to get rid of those bad inks. Thereafter, the recording operation is started.
[0054]
In the case of a color recording head (No in Step 120), it is determined whether the count value of the timer T has exceeded 5 days (Step 130), and if it has not exceeded 5 days (Step 130). No), recording is performed without performing purging (step 190). That is, in the case of a color recording head, it is estimated that many bubbles in the ink in the ink supply path have been discarded by the previous purging, or the bubbles affect the ink ejection performance of the nozzle. Therefore, the number of days that is a criterion for whether or not to perform purging is longer than three days that is a criterion for whether or not to perform purging in the case of a black recording head. Set to 5 days to eliminate unnecessary ink suction.
[0055]
If the count value of the timer T is longer than 5 days and not longer than 10 days (No in step 140), the parsing frequency data indicating the number of times of one purging is read from the parsing table 91 and executed once. (Step 150). Further, when the count value of the timer T is longer than 10 days and not longer than 15 days (No in Step 160), the parsing number data indicating the number of times of purging is read from the purging table 91, and the parsing is performed twice. However, if the count value of the timer T exceeds 15 days (Yes in step 160), the parsing number data indicating the number of times of purging is read from the parsing table 91, and the parsing is executed three times. (Step 180). When purging is completed, the timer T is reset (step 200), and the timer T starts counting again (step 210).
[0056]
Thus, the longer the time elapsed since the previous purging was executed, the more the number of purgings is executed. In other words, the longer the elapsed time from the previous purging, the larger the bubbles in the ink in the ink supply path or the more bubbles are estimated to be generated. A lot of ink is sucked to get out.
[0057]
As described above, according to the recording apparatus 10 of the present embodiment, the purging conditions can be varied according to the type of the recording head. Even in some cases, the recording quality can be further improved. In addition, useless suction of ink can be eliminated. In addition, the longer the elapsed time from the execution of purging to the input of recording data, that is, the longer the non-use period of the recording apparatus, the more ink can be sucked out and the bubbles in the ink can be discarded. Even when the non-use period is long or short, the ink ejection function of the nozzle can be recovered to improve the recording quality.
[0058]
The recording apparatus 10 includes a data creation unit (so-called personal computer) and a recording unit (so-called printer) connected to the data creation unit, and the control means including the CPU of the data creation unit performs control of the present invention. It is also possible to execute all of them, or to read the purging operation of the recording unit and measure the time until the recording operation command. In this case, the program that causes the data creation unit to operate in this way is provided on a computer-readable storage medium such as magnetism.
[0059]
By the way, in the said embodiment, step 100-step 210 performed by CPU70 function as an ink suction means of this invention.
[0060]
【The invention's effect】
As described above, according to the present invention, the amount of ink corresponding to the type of the recording head is sucked so that the ink used can be easily bubbled. Soon Even if there is a difference, it is possible to realize a recording apparatus that can improve recording quality and eliminate unnecessary suction of ink.
[0061]
[0062]
[Brief description of the drawings]
FIG. 1 is a part of the internal structure of a recording apparatus according to an embodiment of the invention. Take FIG.
FIG. 2 is a block diagram showing a control system of the recording apparatus shown in FIG.
FIGS. 3A and 3B are explanatory diagrams showing the configuration of purging tables 90 and 91 stored in a ROM 74. FIGS.
FIG. 4 is a flowchart showing control details of purging.
[Explanation of symbols]
10 Recording device
11 Recording paper
12 Platen roller
20 Recording head
21 Black recording head
22 Yellow recording head
23 Magenta recording head
24 Cyan recording head
29 Carriage
30 Ink absorption pad
40 Purging mechanism
41 Suction cap
42 cam
43 Pump
50 Wiper members
61 cap
70 CPU
88 Ink cartridge sensor
T timer

Claims (3)

A recording head provided with a plurality for each type of ink the ink contained in an exchangeable ink cartridge performs recording by discharging onto a recording medium from a nozzle communicating with the ink cartridge, or the nozzles of the recording head come In an ink jet recording apparatus provided with an ink suction unit that sucks ink and makes the ink discharge state good.
The plurality of recording heads include one recording head connected to an ink cartridge containing one ink, and another recording head connected to an ink cartridge containing another ink that is more likely to foam than the one ink. In addition,
A timer for measuring a time from when the ink suction means performs an ink suction operation until recording data is input;
When the recording data is input, the ink suction means detects the time measured by the timer, sucks more ink as the detection time is longer, and sets the suction amount corresponding to the detection time, When the recording head is operated so that the number of recording heads is larger than that of the other recording head, and when the recording data is not input, a suction operation command is received from the user. The suction amount from the one recording head and the suction amount from the other recording head are equal to each other, and these suction amounts are equal to the minimum suction amount of the suction operation performed when the recording data is input. Work to be
An ink jet recording apparatus, characterized in that The ink suction means is configured such that when the ink cartridge is replaced when recording data is not input, the suction amount from the other recording head is larger than the suction amount from the one recording head, and 2. The ink jet recording apparatus according to claim 1, wherein the suction amount operates so as to be larger than a maximum suction amount of a suction operation performed when recording data is input . 3. The ink jet recording apparatus according to claim 1, wherein the ink suction means increases the suction amount by increasing the number of times of suction .

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