JP3384448B2 - Ink jet recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus provided with a recording head for ejecting ink droplets toward a recording sheet based on print data, and more specifically, for clogging of nozzle openings of the recording head. The present invention relates to a flushing control technique for preventing it.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used for many types of printing, including color printing, because of their relatively low noise during printing and the ability to form small dots with high density. 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 relatively moves a recording sheet with respect to the recording head, and the recording head is based on print data. Recording is performed by moving ink droplets to form dots by ejecting ink droplets onto the recording paper.

A recording head for ejecting black, yellow, cyan, and magenta inks is provided on the carriage, and not only text printing with black ink but also changing the ejection ratio of each ink enables full-color printing. There is.

In such an ink jet type recording head, since the ink pressurized in the pressure generating chamber is ejected from the nozzle as an ink droplet onto the recording paper to perform printing, the ink viscosity resulting from the evaporation of the solvent from the nozzle opening is used. Rise of
There is a problem in that the nozzle openings are clogged due to solidification of ink, adhesion of dust, mixing of air bubbles, and the like, resulting in defective printing.

For this reason, the ink jet type recording apparatus is provided with a capping means for sealing the nozzle opening of the recording head during non-printing, and a wiping member for cleaning the nozzle forming surface if necessary. This capping means not only functions as a lid for preventing the ink in the nozzle opening from drying, but also when the nozzle opening is clogged, the nozzle forming surface is sealed by the capping means and the suction pump is operated. It also has a function of suctioning and discharging the ink from the nozzle opening by the negative pressure to eliminate clogging of the nozzle opening.

The forcible suction / ejection process of ink for eliminating clogging of the recording head is called a cleaning operation. For example, when printing is restarted after a long pause of the recording apparatus, or when the user prints. This is executed when the cleaning switch is operated after recognizing a bad condition, and after wiping the ink from the recording head, the wiping member made of an elastic plate such as rubber wipes the nozzle forming surface of the recording head. Be seen.

Further, the recording head has a function of applying a drive signal not related to printing to eject ink droplets, which is called a flushing operation, and is performed by a wiping operation by a wiping member during a cleaning operation. It is possible to recover the irregular meniscus near the nozzle opening of the head, or to perform the operation at regular intervals to prevent clogging due to thickening of ink at the nozzle opening where ink droplets are rarely ejected during printing. is there.

[0008]

As described above, in the ink jet type recording apparatus, when the printing apparatus is not printing or when the operating power supply to the recording apparatus is not turned on (power off state), the recording head is moved by the capping means. It is configured to seal the nozzle forming surface. In addition, in order to reduce evaporation of the ink solvent at the nozzle opening from the recording head in the capping state as much as possible, a predetermined amount of ink is ejected from the recording head immediately before the cap operation, and the inside of the capping means is discharged. A control means for maintaining a wet state is adopted.

In this case, the drive signal generated by the flushing control means executes the idle discharge of ink from all the nozzle openings of the recording head, so that the ink droplets are ejected into the capping means. .

By the way, the printing ink for keeping the inside of the capping means in a wet state contains polyhydric alcohols such as glycerin or diethylene glycol as a moisturizer. These polyhydric alcohols have a property of absorbing (embracing) water in the air, and by using this as an ink solvent, mainly to prevent clogging of fine nozzle openings in the recording head. Is taken into consideration.

On the other hand, when the printing ink is flushed into the capping means as described above in the state where the recording head is held in the capping state,
The above-mentioned glycerin or diethylene glycol contained in the flushed ink absorbs moisture in the internal space of the capping means by its moisturizing action, and thereby rather promotes evaporation of moisture in the ink at the nozzle openings of the recording head. Have been found by the inventor of the present case.

This state is schematically shown in FIG.
Reference numeral 20 in FIG. 12 is a recording head, and a nozzle plate 20b as a nozzle forming surface of the recording head is arranged on the lower side surface of the recording head 20, and a plurality of nozzle openings 20c are formed in the nozzle plate 20b. Has been formed.

On the other hand, reference numeral 9 is a capping means,
The capping means is provided with a cap case 9a formed in a substantially rectangular shape with an open upper surface, and a cap member 9b made of an elastic member such as a rubber material housed in the cap case 9a. Is formed so that its upper edge slightly protrudes from the cap case 9a to form a nozzle sealing surface. The ink absorber 9c made of a porous material is housed in the inner bottom of the cap member 9b.

Further, on the bottom bottom of the cap case 9a,
A suction port 9d is formed so as to penetrate the cap case 9a and the cap member 9b, respectively. A tube 23 is connected to the suction port 9d, and a suction pump is connected via the tube 23.

The cap case 9a is held on a slider 9e, and the slider 9e is rotatably supported by the other end of an arm 9f whose one end is supported by a rotation fulcrum. Then, as the carriage moves to the home position side, the capping means 9 also moves in the same direction via the arm 9f, whereby the cap member 9b rises to the recording head side, and the nozzle plate of the recording head. To act as a seal. When the carriage moves from the home position to the print area side,
Due to the action of a spring member (not shown), the capping means 9 is unsealed from the recording head and descends contrary to the above-described operation.

In FIG. 12 showing the capping state,
The moisturizer contained in the flushed ink (see FIG. 12).
(Shown as a large circle) is held in a state of being impregnated with the ink absorbing material 9c. As described above, this moisturizer has a property of absorbing water in the internal space of the capping means, and therefore water in the ink (indicated by small circles in FIG. 12) in the nozzle openings of the recording head 20 is particularly absorbed. Acts to absorb.

As shown schematically in FIG. 12, in the conventional recording apparatus, even if the nozzle opening is sealed by the capping means, the moisturizing agent in the flushed ink is damaged as described above. However, there is a problem that ink thickening at the nozzle opening portion of the recording head is rather promoted and the nozzle opening is clogged to cause defective printing.

The present invention has been made based on the above technical point of view, and evaporation of water in the ink at the nozzle opening of the recording head caused by the moisturizing agent contained in the printing ink flushed in the capping means. It is an object of the present invention to provide an ink jet recording apparatus provided with a flushing control unit capable of suppressing the occurrence of printing defects as effectively as possible and effectively reducing the occurrence of printing defects.

[0019]

In order to achieve the above object, the present invention provides an ink jet recording head mounted on a carriage for ejecting a plurality of types of ink from nozzle openings based on print data, and a pause of the apparatus. An ink jet recording apparatus comprising a capping means for sealing a nozzle forming surface of the recording head during a period, and a control means for generating a command signal for ejecting an ink droplet from the nozzle opening of the recording head into the capping means. There
The control means controls the same amount of ink as the capping means.
Of the remaining capping means when the
It is configured to generate a command signal for selecting and ejecting the ink having the smallest amount of the wet component from the plurality of types of ink.

[0020]

Further, in another preferred embodiment, the control means gives a command to increase the ejection ratio of ink having a composition having a small moisturizing component when ejecting a plurality of kinds of ink as the moisturizing liquid from the recording head. Configured to generate a signal.

Furthermore, in another preferred embodiment, the control means, when ejecting a plurality of types of ink as the moisturizing liquid from the recording head, gives a command signal for increasing the ejection ratio of ink having a high water content. Is configured to generate.

In any of the above-mentioned embodiments, the control means preferably ejects the ink that is most likely to thicken in the capping means in a state where the nozzle forming surface of the recording head is sealed by the capping means. A command signal for ejecting ink as a moisturizing liquid is generated at the nozzle facing position.

Further, the control means generates a command signal for ejecting ink as a moisturizing liquid to a position facing each nozzle of the recording head in the capping means in a state where the nozzle forming surface of the recording head is sealed by the capping means. May be configured to do so. Further, the control means may be configured to generate a command signal for ejecting the ink as the moisturizing liquid substantially uniformly in the capping means. In this case, preferably, the control means is adapted to generate a command signal for ejecting ink as a moisturizing liquid in association with the movement of the carriage.

In the ink jet recording apparatus according to the present invention, it is also possible to suitably adopt a mode in which a moisturizing liquid is ejected into the capping means instead of the ink as the moisturizing liquid. In this case, an aqueous solution containing a surfactant and a preservative is used as the moisturizing liquid.

Further, it is preferable that the recording head has a nozzle opening for receiving the supply from the tank for storing the exclusive moisturizing liquid and discharging the exclusive liquid. Further, it is preferable that the tank for storing the exclusive moisturizing liquid is integrally formed in the ink cartridge for storing the printing ink.

In any of the above-mentioned modes using the moisturizing liquid, the control means preferably has the highest viscosity in the capping means when the nozzle forming surface of the recording head is sealed by the capping means. A command signal for discharging the dedicated moisturizing liquid is generated at a position facing the nozzle that discharges the easy ink.

Further, the control means generates a command signal for ejecting a moisturizing dedicated liquid to a position facing each nozzle of the recording head in the capping means in a state where the nozzle forming surface of the recording head is sealed by the capping means. It may be configured as follows. Further, the control means may be configured to generate a command signal for ejecting the moisturizing dedicated liquid substantially uniformly in the capping means.

Further, it is preferable that an absorbing material for holding the ink or the dedicated liquid for moisturizing is arranged in the capping means.

On the other hand, a nozzle opening for ejecting ink as a moisturizing liquid or a moisturizing liquid in the recording head mounted on the carriage may be formed on the side closer to the capping means from the print area. preferable. In addition, a suction port communicating with the negative pressure generating unit is formed in the capping unit, and the suction port discharges the ink that is most likely to thicken when the nozzle forming surface of the recording head is sealed by the capping unit. It is preferable that the recording head is arranged at the farthest position from the nozzle facing position of the recording head.

According to the ink jet type recording apparatus constructed as described above, the ink of the composition having the smallest moisturizing component among the plurality of recording inks when capping the recording head when the recording apparatus shifts to the rest state, Alternatively, the ink having the highest water content or the ink having the highest weight ratio of the water content to the moisturizing component is selected and ejected into the capping means.

When a plurality of inks are ejected, the ejection ratio of the ink having a composition having a small moisturizing component is increased, or the ejection ratio of the ink having a high water content is controlled to be increased.

By performing such flushing control, the proportion of the moisturizing component in the internal space of the capping means can be reduced and the proportion of the water composition can be increased, whereby the ink solvent at the nozzle openings of the recording head can be increased. It effectively acts to suppress the evaporation of water.

Further, by ejecting the ink selected as described above to a position in the capping means facing the nozzle for ejecting the ink that is most likely to thicken in the capping state, the evaporation of the ink solvent in the nozzle is performed. Can be further suppressed.

Further, instead of the printing ink, for example, a tank for storing a moisturizing liquid containing a surfactant or the like is formed integrally with, for example, an ink cartridge, and a nozzle for ejecting the moisturizing liquid is used as described above. The effect can be remarkably enhanced by performing such a flushing operation.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an ink jet type recording apparatus adopting a flushing control means according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 is a perspective view showing the overall configuration of an ink jet recording apparatus to which the present invention is applied. In the figure, reference numeral 1 is a carriage, and this carriage 1 is a carriage motor 2
It is configured to be reciprocally moved in the axial direction of the platen 5 while being guided by the guide member 4 via the timing belt 3 that reciprocates by the driving of the.

The side of the carriage 1 facing the recording paper 6,
That is, an ink jet recording head, which will be described later, is mounted on the lower surface of the carriage 1, and a black ink cartridge 7 for supplying ink to the recording head and a color ink cartridge 8 are detachably mounted on the lower surface thereof. ing.

Reference numeral 9 in the drawing denotes a capping means arranged at a home position outside the printing area, and below the capping means 9, a negative pressure generating means for giving a negative pressure to the capping means 9. The suction pump 10 is disposed.

The capping means 9 functions not only as a lid for sealing the nozzle forming surface of the recording head to prevent the nozzle openings from drying during the idle period of the recording apparatus, but also as an ink receiver during the flushing operation. By applying a negative pressure from the suction pump 10 to the recording head,
It also has a function as a cleaning unit for sucking and discharging the ink from the recording head.

Further, a strip-shaped wiping member 11 made of an elastic member such as rubber is arranged near the printing area side of the capping means 9 and slides on the nozzle forming surface of the recording head as required. In contact with the nozzle forming surface, dust such as paper powder or ink, or the like can be wiped off for cleaning.

FIG. 2 is a sectional view showing a recording head mounted on the carriage 1 and an ink cartridge mounted on the recording head. A nozzle plate 20b forming a nozzle forming surface of the recording head 20 is arranged on a lower side surface of a head case 20a forming the recording head 20, and a plurality of nozzle openings 20c are formed in the nozzle plate 20b. . In addition, each nozzle opening 20
Corresponding to c, the actuator 20d by the piezoelectric vibrator,
It is arranged in the head case 20a. An ink communication channel 20e is formed in the head case 20a from the nozzle opening 20c and its actuator 20d portion to the upper part.

On the upper surface of the head case 20a, four hollow needles 21 are arranged in an upright state, and each ink communication channel 20e formed in the head case 20a.
Are communicated with the ink flow path in each hollow needle 21. In addition, an ink introduction hole 21a is provided on the top of each hollow needle 21.
The ink from the ink cartridge is introduced into the hollow needle 21 through the ink introduction hole 21a and is supplied to the nozzle opening 20c of the recording head through the ink communication channel 20e. It is configured. A filter member 22 for removing dust and the like is arranged in the ink flow path between each hollow needle 21 and the head case 20a.

The ink supply needle 21 at the left end in FIG.
It is for supplying black ink, and is configured so that the black ink cartridge 7 can be mounted toward the ink supply needle 21 from above. Most of the upper portion of the black ink cartridge 7 is formed in the ink storage chamber 7a.
The porous member 7b is housed in a and the porous member 7
Ink is stored in a state where b is impregnated with black ink.

An opening 7c is formed on the lower side of the ink storage chamber 7a, and a rubber seal member 7d is fitted in the opening 7c. A film member 7e is attached to the lower end of the opening 7c and is sealed so that the ink solvent inside does not vaporize during storage of the cartridge.

As shown in FIG. 2, when the cartridge 7 is pushed in from above, the ink supply needle 21 penetrates the film member 7e, and the rubber seal member 7d mounted on the cartridge 7 supplies the ink. Needle 21
The cartridge 7 is put in a loaded state by being joined to the periphery of the cartridge.
Then, the ink is supplied from the ink cartridge 7 to the recording head side through the ink lead-out hole 21a formed at the tip of the ink supply needle 21.

On the other hand, in the color ink cartridge 8,
As shown in FIG. 2, ink storage chambers for individually storing cyan, magenta, and yellow color inks are formed in order from the left, and these ink storage chambers are integrally formed. The respective configurations are the same as the black ink cartridge 7 described above. Therefore, detailed description of each configuration will be omitted.

In this color ink cartridge 8 as well, in the state shown in FIG. 2, by pushing in from above, the remaining three ink supply needles 21 established on the head case 20a of the recording head are set to the respective mounted states. Then, each color ink is supplied to the recording head side.

FIG. 3 shows a state in which the nozzle forming surface of the recording head is sealed by capping means in a state where the ink cartridges 7 and 8 are mounted. The peripheral configuration of the recording head 20 and the ink cartridges 7 and 8 is as described in FIG. 2, and the configuration of the capping means indicated by reference numeral 9 is as described with reference to FIG.

In FIG. 3, the tube 23 connected to the suction port 9d is connected to the suction pump 10, and the discharge side of the suction pump 10 is connected to a waste ink tank described later. As the suction pump 10, a so-called tube pump is used in which the rollers sequentially crush the tubes arranged in an arc shape to generate a negative pressure. By this operation, the internal space of the capping means can be sucked to a negative pressure, and the recording is performed. A cleaning operation for sucking and discharging ink from the nozzle openings 20c of the head 20 is executed. Further, while the suction pump 10 is stopped, the internal space of the capping means 9 is maintained in a state of communicating with the atmosphere via the pump tube.

Next, FIG. 4 is a block diagram showing an example of a control circuit, particularly a flushing control means, mounted on the recording apparatus having the above-mentioned structure. The carriage 1, the carriage motor 2, the timing belt 3, the ink cartridges 7 and 8, the capping means 9, the suction pump 10 and the recording head 20 which have already been described with reference to FIG. To do.

In FIG. 4, reference numeral 40 denotes print control means, which print control means 40 generates bitmap data based on print data provided from the host computer of the recording apparatus, and based on this data, head drive means. A drive signal is generated at 41, and the recording head 2
Ink is discharged from 0. The print control means 40 sends a control signal to the carriage motor control means 42 to control the drive of the carriage motor 2.

The head driving means 41 is constructed to receive a flushing command signal from the flushing control means 43 and to output a driving signal for flushing operation to the recording head 20 in addition to the driving signal based on the print data. ing.

Reference numeral 44 is a cleaning control means,
Cleaning (hereinafter also referred to as CL) command detection means 45,
In response to the signals from the elapsed time after CL detecting means 46 and the cumulative cap opening time detecting means 47, the pump driving means 4
8 is operated to drive the suction pump 10.

Here, the post-CL elapsed time detecting means 46 is
Immediately after the cleaning is performed by the cleaning control means 44, a cleaning end signal is sent from the cleaning control means 44 to measure the elapsed time after cleaning. Also, the cumulative cap opening time detecting means 47
Is for counting the accumulated time during which the print head is released from the capping means for printing by the print control means 40. When the print head is released from the capping means, time counting is started and printing is completed. When the recording head is capped, it stops timing.

The cumulative cap opening time detecting means 47 receives a flushing command from the printing control means 40 when the cleaning control means 44 performs the cleaning operation or immediately after capping after the printing operation continues for a long time. Issued and reset if flushing is performed.

The flushing control means 43 outputs the flushing command from the print control means 40 immediately before the printing operation is started or when the printing operation is continued for a certain period of time, or when the printing operation is completed and the recording head is turned off. Immediately before sealing by the capping means 9, or when a suction end signal is output from the cleaning control means 44 and a time-up signal is output from a flushing hold timer 49, which will be described later, or when the operating power supply of the recording apparatus is turned on. Operates when turned on.

Then, the carriage motor control means operates according to a command from the print control means 40 to move the recording head 20 mounted on the carriage 1 to the flushing position, that is, the capping position, and a predetermined number of times from the nozzle opening of the recording head. By blank-jetting ink droplets, the nozzle openings are prevented from being clogged, the clogging is eliminated, and the ink as a moisturizing liquid is driven into the capping means.

Further, the flushing hold timer 49 starts the time counting operation at the stage when the cleaning process is completed, and measures the time corresponding to the spontaneous disappearance of the bubbles generated in the vicinity of the nozzle opening of the recording head 20 in the cleaning process. It is configured to increase the time in stages.

Reference numeral 50 in FIG. 4 indicates a cleaning command switch provided on the control panel or the like of the case, and when the user recognizes a faint print or the like, by pushing this switch, the CL command detecting means. Four
5 is operated to execute the manual cleaning operation. Further, reference numeral 25 in FIG.
Indicates a waste ink tank arranged on the discharge side of the suction pump 10.

Next, FIG. 5 shows an example of the composition of the printing ink which is flushed in the capping means by the action of the flushing control means shown in FIG. 4 and used as a moisturizing liquid. In FIG. 5, the components (weight ratio) of each ink of black (Black), cyan (Cyan), magenta (Magenta), and yellow (Yellow) are shown in order from the left, and the lower three lines in FIG. In particular, the relationship between glycerin and diethylene glycol as a moisturizing component and the water composition is extracted and expressed.

As can be understood from the composition shown in FIG. 5, the ink having the least moisturizing component (glycerin + diethylene glycol) is black, and the ink having the highest water composition is yellow. The ink having the highest weight ratio [water / (glycerin + diethylene glycol)] of the moisture composition to the moisturizing component is black.

From the above viewpoints, FIG. 6 schematically shows an embodiment in which only the yellow ink having the highest water content is flushed into the capping means as the moisturizing ink. The reference numerals of the parts shown in FIG. 6 correspond to the parts already described, and the description thereof will be omitted. FIG. 6 shows an embodiment in which a yellow ink as a moisturizing liquid is ejected to a position facing each nozzle of the recording head in the capping means in a state where the nozzle forming surface of the recording head is sealed by the capping means. .

That is, (a) shows a state in which the yellow ink is ejected at the nozzle facing position of the black ink in a state where the nozzle forming surface of the recording head 20 is sealed by the capping means 9. This is because the number of drive pulses supplied from the carriage motor control means 42 in the control means shown in FIG. 4 determines the number of revolutions (step amount) of the carriage motor, which is a pulse motor. The nozzle of the yellow ink in the head 20 is set at the position shown in FIG. 6A (position facing the nozzle of the black ink in the capping state).

Then, in this state, the flushing control means 43 supplies a flushing control signal to the actuator 20d corresponding to the nozzle of the yellow ink, and the flushing operation of the yellow ink is performed on the ink absorbing material 9c as shown in the figure.

Further, FIG. 6B shows a state in which the yellow ink is ejected to the nozzle facing position of the cyan ink in the state where the nozzle forming surface of the recording head 20 is sealed by the capping means 9. 6 (c) is the same as the position of the magenta ink facing the nozzles.
Similarly, (d) shows a state in which the yellow ink is being ejected at the nozzle facing position of the yellow ink.

Also in the cases shown in (b) to (d), as in the case shown in (a), the yellow ink is supplied from the flushing control means 43 after the predetermined drive pulse is supplied from the carriage motor control means 42. It can be realized by supplying the flushing control signal to the actuator 20d corresponding to the nozzle of.

In the embodiment shown in FIG. 6, in the state where the nozzle forming surface of the recording head is sealed by the capping means, yellow as a moisturizing liquid is provided in the capping means at a position facing each nozzle of the recording head. Although the flushing mode in which the ink is sequentially ejected is shown, in the case, the flushing mode may be adopted only at the nozzle facing position of the black ink that is most likely to thicken, that is, the position shown in FIG. 6A.

Further, almost uniformly in the capping means,
It is also effective to eject, for example, yellow ink as the moisturizing liquid, and in this case, a command signal for ejecting the ink as the moisturizing liquid is generated in association with the movement of the carriage.

In the above-described embodiment, the yellow ink having the highest water content is used for flushing, but the black ink, which is the ink having the smallest moisture retaining component, is used for flushing. You can also In this case as well, it can be realized by supplying a predetermined drive pulse from the carriage motor control unit 42 and then supplying a flushing control signal from the flushing control unit 43 to the actuator 20d corresponding to the black ink nozzle. .

Further, it is also effective to discharge the ink having the highest weight ratio of the water composition to the moisturizing component as the moisturizing liquid into the capping means. In this case, the ink composition shown in FIG. It is black ink.

In the above description, one of a plurality of types of printing ink is flushed as a moisturizing liquid, but a plurality of types of printing ink are ejected from the recording head as a moisturizing liquid. In this case, the same effect can be obtained by controlling so that the ejection ratio of the ink having a composition with a small moisturizing component (black ink according to the example shown in FIG. 5) is increased. it can.

Further, the same effect can be obtained by controlling the ejection ratio of the ink having a high water content (yellow ink according to the example shown in FIG. 5) to be high. In this case, the flushing control means 43 shown in FIG. 4 changes the form of the ejection control signal given to the actuator of each nozzle, or controls so as to give a difference in the number of ejections, so that the ink from each nozzle is ejected. It is possible to control the ratio of the discharge amount of

In the example of the ink composition shown in FIG. 5, glycerin and diethylene glycol are contained as moisturizing components, but printing inks containing ethylene glycol and propylene glycol as moisturizing components are also present. In this case, these moisturizing components may be added to determine which ink is most suitable for the flushing operation.

Next, FIGS. 7 to 10 show a color printing recording apparatus using three color printing inks of cyan, magenta, and yellow, and a dedicated moisturizing liquid was used as the moisturizing liquid without using the printing ink. It shows an embodiment. 7 to 10, parts corresponding to the parts already described are indicated by the same reference numerals, and therefore,
The description will be omitted as appropriate.

As shown in FIGS. 7 to 10, a tank 27 for storing a dedicated moisturizing liquid is attached adjacent to the color ink cartridge 8 in which cyan, magenta, and yellow inks are stored in order from the left. . Although the tank 27 for exclusive use of the moisturizing liquid is illustrated as being separated from the color ink cartridge 8 in the figure, it is convenient to handle this tank 27 integrally with the ink cartridge 8.

The exclusive moisturizing liquid stored in the tank 27 is
The head case 20a is composed of an aqueous solution containing a surfactant and an antiseptic agent, and the head case 20a has a communication channel 2 for color ink.
Similar to 0e, a connection channel 20g for the exclusive moisturizing liquid is formed, and a nozzle opening 20h for ejecting the exclusive moisturizing liquid is also formed in the nozzle plate 20b. That is, from the tank 27 that stores the dedicated moisturizing liquid to the nozzle opening 20h
The supply path to the print ink supply path is the same as the supply path of the printing ink.

The example shown in FIG. 7 shows a mode in which the moisturizing liquid is flushed to the nozzle facing position of the ink that is most likely to thicken in the capping state. Among the color inks, the ink whose viscosity is most likely to increase is cyan, for example, and the moisturizing-dedicated liquid is ejected from the nozzle opening 20h to the nozzle facing position of the cyan ink in the capping state.

Further, it is also possible to adopt a construction in which the moisturizing-dedicated liquid is discharged in order not only to the nozzle facing position of the ink that is most likely to thicken, but also to the nozzle facing position of the other ink.
8 and 9 show a flushing operation of the dedicated moisturizing liquid to the nozzle facing position of the cyan ink shown in FIG.
The figure shows a state in which the moisturizing-dedicated liquid is flushed in order to the nozzle facing positions of magenta and yellow. And
As shown in FIG. 10, when the carriage is further moved to the home position side, the flag pieces 9g arranged in the upright state on the capping means 9 are moved to the head case 20a.
Of the recording head 20 and the capping means 9 is further raised to seal the nozzle plate of the recording head 20.

In addition, almost uniformly in the capping means,
Discharging the moisturizing dedicated liquid is also effective, and in this case, a command signal for discharging the dedicated liquid is generated in conjunction with the movement of the carriage.

The nozzle openings for ejecting the printing ink or the moisturizing liquid as the moisturizing liquid in the recording head mounted on the carriage are preferably formed on the side closer to the capping means from the printing area. . This is because when the printing ink as the moisturizing liquid or the moisturizing liquid is sequentially flushed into the capping means, flushing is performed from the first nozzle opening while the carriage is moving from the print area side toward the home position side. be able to.

Because of this, the device can be designed rationally and, with further movement of the carriage, FIG.
The capping state can be set as indicated by 0, which contributes to improvement of the reliability of the device and simplification.

Therefore, when the above-mentioned structure is adopted and the black ink is ejected as the moisturizing liquid, the arrangement is as shown in FIG. That is, the arrangement state of the black ink cartridge 7 and the color ink cartridge 8 is replaced with the arrangement shown in FIG. 3, and the black ink cartridge 7 is arranged on the home position side (right side in FIG. 11). It

In addition to this, the suction port 9d communicating with the suction pump formed in the capping means 9 ejects the ink that is most likely to thicken in the state where the nozzle forming surface of the recording head is sealed by the capping means. It is desirable that the recording head is arranged at the farthest position from the nozzle facing position of the recording head.

This is because the tube connected from the capping means to the suction pump is well sealed with the nozzle forming surface during capping by the capping means.
It must be made of a relatively soft material. Many of the relatively soft materials that can be used as the tube have a low gas barrier property and have large factors such as water evaporation. Therefore, it is preferable to increase the distance between the nozzle row of the ink that is most likely to thicken and the suction port that communicates with the suction pump.

The embodiment shown in FIG. 11 shows a preferable example thereof, in which the suction port 9 is located at the farthest position from the nozzle facing position of the recording head for ejecting the black ink that is most likely to thicken.
d is arranged.

[0086]

As is apparent from the above description, the ink jet type recording apparatus according to the present invention is, for example, the most moisturizing component among a plurality of inks when capping the recording head when the recording apparatus shifts to the rest state. Ink having a low composition is selected and ejected into the capping means. Similarly, the moisturizing liquid may be discharged into the capping means. As a result, it is possible to effectively suppress the evaporation of the ink solvent in the nozzle openings of the recording head in the capped state, and it is possible to provide a highly reliable recording apparatus that does not cause a print failure or the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic configuration of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a cross-sectional view showing a recording head portion and an ink cartridge mounted on the recording head portion in the recording apparatus shown in FIG.

FIG. 3 is a cross-sectional view of a state in which a nozzle forming surface of a recording head with an ink cartridge attached is sealed by a capping unit.

FIG. 4 is a block diagram showing an example of a control circuit mounted on the recording apparatus shown in FIG.

FIG. 5 is a composition diagram showing an example of an ink composition used in a recording apparatus.

6A to 6C are cross-sectional views sequentially showing an example of a flushing operation when ink is used as a moisturizing liquid.

FIG. 7 is a cross-sectional view showing an example of a flushing operation when a moisturizing liquid is used.

8 is a sectional view showing an example of a flushing operation following the state shown in FIG.

9 is a sectional view showing an example of a flushing operation following the state shown in FIG.

FIG. 10 is a cross-sectional view showing a state in which a capping state is established subsequent to the state shown in FIG.

FIG. 11 is a cross-sectional view showing a preferable arrangement configuration of the ink cartridge.

FIG. 12 is a schematic diagram for explaining a problem after the flushing operation in the conventional device.

[Explanation of symbols]

1 carriage 2 Carriage motor 3 Timing belt 6 recording paper 7 Black ink cartridge 8 color ink cartridges 9 Capping means 9c ink absorber 10 Suction pump (negative pressure generating means) 11 Wiping member 20 recording head 20a head case 20b nozzle plate 20c nozzle opening 20d actuator 20h nozzle opening 21 hollow needle 25 waste ink tank 27 Moisturizing Dedicated Liquid Tank 40 print control means 41 Head drive means 42 Carriage motor control means 43 Flushing control means 44 Cleaning control means 45 Cleaning command detecting means 46 means for detecting elapsed time after cleaning 47 Cumulative cap opening time detection means 48 Pump drive means 49 Flushing hold timer

Claims (2)

(57) [Claims] 1. An ink jet recording head mounted on a carriage for ejecting a plurality of types of ink from nozzle openings based on print data, and a capping means for sealing a nozzle forming surface of the recording head during an idle period of the apparatus. An inkjet recording apparatus comprising: a control unit that generates a command signal for ejecting an ink droplet from a nozzle opening of the recording head into the capping unit, wherein the control unit supplies the same amount of ink to the capping unit. An ink jet type recording apparatus for generating a command signal for selecting and ejecting an ink having the smallest amount of a moisturizing component remaining in the capping unit when ejected from the plurality of types of ink. 2. The ink jet recording apparatus according to claim 1, wherein the ink selected and ejected from the plurality of types of ink is an ink having a highest water content or an ink having a lowest moisture retention component composition.