JPH0781085A - Liquid emitting device - Google Patents

Abstract

PURPOSE:To outstandingly prolong the service life of a head and a wiping-off means and increase the production speed and perform stable emission over a long period of time by providing a head wiping-off means and a means changing the wiping-off conditions of a liquid emitting surface due to the wiping-off means. CONSTITUTION:An opening 71B is provided to the surface 71A coming into contact with a cleaning member 70 of a holder 71 and connected to a suction tube 74 through a duct 71C. The washing soln. or ink infiltrated in the cleaning member 70 is discharged in the direction shown by an arrow A by a suction means 82 composed of a pump. The suction means 82 may be a discharge means connecting a porous member or a fibrous member to the cleaning member to form a drain passage and discharging the washing soln.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejecting apparatus using a liquid ejecting head for ejecting a liquid such as ink, and more specifically, a liquid ejecting device for a print medium such as paper, cloth, non-woven fabric and OHP paper. The present invention relates to a printing device that prints. In particular, the present invention provides an invention effective for a printing apparatus that prints continuously for a long time or on a cloth having a print width of 1 m or more. Specific applicable equipment includes office equipment such as printers, copiers and facsimiles, mass production equipment such as textile printing equipment, and equipment that drives an object using discharged liquid.

[0002]

2. Description of the Related Art As a conventional liquid ejecting apparatus, there is an apparatus which ejects a liquid for recording or a special liquid is ejected and used. In general, since the ejection portion that ejects the liquid is extremely small, a state in which the dye or the content mixed in the liquid is fixed, or a foreign substance is attached may cause ejection failure, The problem that the ejected liquid cannot be used efficiently, for example, recording failure occurs in the recording apparatus. Normally, before these problems occur, the liquid is forcibly discharged by suction, pressurization, etc., which is known as recovery means, or the discharge area with the discharge portion is cleaned or the discharge portion is discharged at appropriate intervals. It is conceivable to discharge gas or liquid to the area.

[0003]

However, the liquid material is ejected to the ejection portion by the above-mentioned recovery means to dissolve and remove the thickened ink and the adhered material in the ejection portion, and the adhered material is removed together with the liquid material. Although flushing is effective, this method also tends to cause the problem that the cleaning liquid is mixed into the discharge nozzles that are in a negative pressure state, the ink density is lowered, and the printing density is lowered.

Further, in the recovery means which does not use the cleaning liquid, the thickened ink is liable to adhere to the vicinity of the nozzles of the ejection head, and clogging and non-ejection of ink are likely to occur.

Further, in the case of forcibly discharging the liquid from the discharge section by suction, if a discharge head having a large number of discharge nozzles is used, the inner volume of the cap that is in close contact with the discharge head at the time of suction becomes large and a predetermined negative pressure control can be performed. It will be difficult.

Further, in the method of only bringing the sponge into contact with the discharge head, when a discharge nozzle with a fine nozzle such as 400 dpi is used, foreign matter may be pushed into the nozzle and discharge failure may occur.

Further, the mist scattered at the time of ink ejection is accumulated on the head surface to prevent the ejection port, and the head surface is wiped by a blade in order to prevent ejection failure or ejection failure state (called wet ejection failure). Although it is possible to do so, when the industrial operation is continued for a long time, the wiped ink loses its escape area and accumulates and thickens, and it is possible to rub the ejection head with a blade to which such thickened ink adheres. Therefore, non-ejection will be caused. Particularly in the case of a color recording apparatus, mist is collected from four heads, which is a serious problem.

Further, since the head and the wiping means repeat rubbing against each other, it is desirable to take measures so as not to reduce their life. It is also desired to improve the throughput of the printing operation by efficiently performing the wiping process.

[0009]

In order to solve at least one of these problems, the present invention is a liquid ejecting apparatus for ejecting a predetermined liquid using a liquid ejecting head, wherein the liquid is ejected. It is characterized by comprising: a wiping means for wiping the surface of the liquid ejection head; and a means for changing the wiping conditions of the liquid ejection surface and the wiping means.

Here, there is provided means for changing the wiping condition during printing.

The cleaning means may further include a cleaning means for cleaning the wiping means, and the cleaning means may have a cleaning liquid discharging means for discharging a cleaning liquid to the wiping means. It may have a liquid absorbing means for sucking the liquid.

Further, the changing wiping condition is a wiping direction between the wiping means and the liquid discharge head, and a relative intrusion amount at a relative wiping speed between the wiping means and the liquid discharge head. The cleaning liquid content of the wiping unit can be set, or the number of times the wiping unit and the head surface are brought into contact with each other.

In addition, as a recovery process for maintaining a good ejection state of the liquid ejection head, a unit for performing a process using the wiping unit, and a pressurization of the ink supply system while using the wiping unit. It can be characterized in that it comprises means for performing processing and means for causing the liquid ejection head to eject ink, and the processing conditions of the means for performing these processing are changed according to the image data. .

[0014]

According to the present invention, in a liquid ejecting apparatus for ejecting a predetermined liquid by using a liquid ejecting head, a wiping means for wiping a liquid ejecting surface of the liquid ejecting head, and the liquid ejecting by the wiping means. By providing the means for changing the surface wiping condition, it is possible to achieve a longer life of the head and the wiping means and an improvement in the production speed. Further, by providing the cleaning means of the wiping means, it is possible to enhance the cleaning effect of the liquid ejection surface of the head and perform stable ejection for a long period of time. Further, when the cleaning means discharges the cleaning liquid to the wiping means, the running cost can be reduced by reducing the cleaning liquid and the waste liquid by changing the wiping condition.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of the configuration of an ink jet printing apparatus as a liquid ejection apparatus to which the present invention is applied.

In the figure, a carriage 1 is equipped with color print heads 2a, 2b, 2c and 2d corresponding to four colors of cyan, magenta, yellow and black, and a guide shaft 3 allows the carriage 1 to move. Supports guidance. Reference numerals 22a, 22b, 22c and 22d denote ejection surfaces of the print heads.

A part of the belt 4, which is an endless belt, is connected to the carriage 1.
Is a drive motor 5 which is a pulse motor driven by a motor driver 23, and moves the guide shaft 3 on the guide shaft 3 through a belt 4 along a print surface of paper, OHP film, cloth or other print medium (hereinafter referred to as print paper) 6. Driven to move. Further, it is provided with a conveyance roller 7 that conveys the print sheet 6, guide rollers 8A and 8B that guide the print sheet 6, and a print sheet conveyance motor 9.

Further, each print head 2a, 2b, 2
A liquid path 10 for ejecting ink droplets toward the print paper 6 is provided in each of c and 2d, and each of the print heads 2a, 2b, 2c and 2d is provided to the liquid path 10.
Corresponding to the ink tanks 11a, 11b, 11c, 11
Ink is supplied from d through the supply tubes 12a, 12b, 12c, 12d. For the means (not shown) provided in each liquid path 10 for generating energy used for ejecting ink, each head driver 24a,
Flexible cable 13 from 24b, 24c and 24d
Ink ejection signals are selectively supplied via a, 13b, 13c, and 13d.

Further, each print head 2a, 2b, 2
The head heaters 14a, 14b, and
14c, 14d (14b, 14c, 14d are not shown in FIG. 1) and temperature detecting means 15a, 15b, 15
c, 15d (15b, 15c, 15d are not shown in FIG. 1) are provided, and the temperature detecting means 15a, 1
The detection signals from 5b, 15c, and 15d are input to the control circuit 16 having a CPU, and the control circuit 16 sends the head heaters 14a, 14b, 14c, and 14d through the driver 17 and the power supply 18 based on this signal. Control heating in.

The capping means 20 is abutted against the ejection opening surface of each print head 2a, 2b, 2c, 2d during non-printing, and the capping means 20 caps the print heads 2a, 2b, 2c, 2d during non-printing. Means 20
Move to the position opposite. At this time, the capping means 20 is driven forward by the cap driver 25 to press the elastic member 44 against the ejection port surface to perform capping.

When the print head is left in the air for a long time, the ink in the nozzle evaporates and the viscosity increases, and the ejection becomes unstable. In order to prevent this, during non-printing, the nozzle part is shut off from the outside air and sealed (capping). Inside the cap portion, there is a liquid absorbing material that is kept wet with ink, and the inside of the cap portion is kept at high humidity to minimize the increase in viscosity of the ink.

Further, when the capping state is left for a long period of time, recovery is performed by pressurizing the ink. That is, when left for a long time, the ink inside the ejection port evaporates and thickens even though capping is performed, although it is slow. In addition, air bubbles may remain inside the discharge port to prevent stable discharge. Therefore, at the start of printing, a pump provided in the ink tank is driven to pressurize the ink, and the thickened ink inside the discharge port and residual bubbles are discharged to the outside of the discharge port. This has an effect of keeping dust and fluff attached to the discharge surface, and even if dust or the like has invaded inside the discharge port, by flushing them to maintain stable discharge.

The clogging preventing means 31 receives the ejected ink when the print heads 2a, 2b, 2c and 2d perform the idle ejection (preliminary ejection) operation. The clogging prevention means 31 is provided for the print heads 2a, 2b, 2c, 2
The capping means 2 is provided with a liquid receiving member 32 as a liquid receiving portion that faces the d and absorbs the ink that has been ejected by the idle.
It is arranged between 0 and the print start position. In addition,
As a material for the liquid receiving member 32 and the liquid holding member 45, a sponge-like porous member, a plastic sintered body, or the like is effective.

The blank discharge is for discharging ink not for the purpose of printing. In order to guarantee the temperature of a region where the temperature is lowered by the liquid discharge flow and the gas discharge flow and to eliminate unnecessary substances in the discharge port. To do. In addition to this, a predetermined drive pulse is applied before the start of printing, and ink is ejected from all ejection ports toward the cap portion and the like (aging operation). In addition, capping may be performed to enhance the wet state of the atmosphere around the discharge port.

An electromagnetic valve 51 for cleaning and a suction pump driver 52 are connected to the cleaning means 50, and the control circuit 16 is connected to each of them.
The cleaning liquid is ejected from the wiping cleaning means 53, and the cleaning liquid is sucked from the cleaning means 50 under the control of.

FIG. 2 shows an example of the structure of the liquid discharge head. Two
Is an ejection head, and 22 is its ejection surface. Reference numeral 101B denotes a nozzle portion in which a plurality of liquid flow paths are arranged in parallel in the vertical direction, and a discharge energy generating element such as an electrothermal converter is provided. Reference numeral 101C is an ink chamber that supplies ink to each liquid flow path in common, and is connected to an ink tank 110 via supply pipes 103 and 104. A gear pump 105 is provided on one of the supply pipes 104, and the print head 2 is supplied to the supply path and the ejection recovery process such as a process of removing air bubbles and dust mixed in the nozzle portion 101B and the like, a process of removing thickened ink, and the like. Of supplying ink to the other ink supply system by pressure and discharging the ink from the discharge port, or the ink supply pipe 1
A process of circulating ink in the ink chambers 03 and 104 or the ink chamber 101C to refresh the ink (hereinafter, referred to as a pressure circulation process) is performed.

3 and 4 show a configuration example of the cleaning means 50. 3 is an explanatory view of the cleaning means 50 when viewed from the main scanning direction of the head 2, and FIG. 4 is a cleaning member 70.
FIG. 3 is an explanatory diagram when the head 2 is viewed from above. The cleaning member 70, which is a wiping unit in this example, is made of a flexible porous body. As the material of the cleaning member, a polymer porous body can be used, and when the polymer porous body is used, the volume change due to absorption of ink mist is not remarkable like a polymer foam, and It is preferable to use a type in which the volume does not change even when absorbing the, for example, a foamed formal resin type is preferable.

As the ink absorber used here, a heat-sintering type polymer porous body can also be used, and examples thereof include low density polyethylene, high density polyethylene, high molecular weight polyethylene, composite polyethylene, polypropylene, Examples thereof include heat-sintered products such as polymethylmethacrylate, polystyrene, acrylonitrile-based copolymers, ethylene-vinyl acetate copolymers, fluororesins, and phenolic resins. It is preferable to use density polyethylene, high density polyethylene, high molecular weight polyethylene, or polypropylene.

Reference numeral 71 is a holder for fixing the cleaning member 70 to the fixing plate 7
Hold it between the two and fix it. 73 is a mounting screw.
The holder 71 is provided with an opening 71B on a surface 71A that abuts the cleaning member 71, and is connected to a suction tube 74 via a conduction path 71C, so that a cleaning liquid or ink impregnated in the cleaning member 70 is sucked by a pump 82. Is configured to be discharged in the direction of arrow A. The suction means 82 may be a discharging means that connects a porous member or a fibrous member to the cleaning member 70 to form a drainage path and discharges the cleaning liquid from the cleaning member.

After the cleaning liquid is sucked by the cleaning liquid, the amount of the cleaning liquid remaining on the cleaning member 70 is appropriately reduced to recover the absorption capacity of ink and foreign matters, and the ejection surface 22 of the head 2 is recovered.
It has become possible to enhance the cleaning effect of. Further, the front end portion 70A of the cleaning member 70 and the ejection surface 22 of the ejection head 2 are L
Since it overlaps for the length shown by, head 2
At the time of scanning, the ejection surface 22 of the head 2 is wiped by this overlap.

A cleaning liquid supply nozzle 75 is supplied with the cleaning liquid 81 in the direction of arrow B from the tank 80, which is a cleaning liquid supply means, through the cleaning liquid supply tube 76 by opening and closing the electromagnetic valve 79, and is directed downward from the discharge portion 75A of the nozzle. And is supplied to the cleaning member 70 for cleaning.

Reference numeral 77 is a tray which is arranged below the cleaning member 70. When the cleaning liquid is supplied from the supply nozzle 75, the cleaning liquid that has not been absorbed by the cleaning member 70 and the ink or foreign matter that has adhered to the cleaning member 70 drops together with the cleaning water. . Reference numeral 78 is a discharge tube for discharging the cleaning liquid received in the receiving tray 77 to a discharge portion (not shown) in the direction of arrow C.

Next, the operation of the ink jet printing apparatus will be described below. In FIG. 5, the print start detection sensor 34 and the capping means detection sensor 3
6 is each print head 2a, 2b, 2c, 2
It is detected that d is at a predetermined capping position. The blank discharge position detection sensor 35 is provided in the print heads 2a, 2
The reference position of the idle discharge operation performed while b, 2c, and 2d move in the scanning direction is detected.

FIG. 6 is a flow chart showing the operation sequence of the technique which is the premise of the present invention using the above-mentioned configuration. First, during standby, the print heads 2a, 2b,
2c, 2d ejection surfaces 22a, 22b, 22c, 22d
Are capped by the capping means 20. When a print signal is input to the control circuit 16, ink pressure circulation is started (step S1). Next, the head cap is opened (step S2).

At the same time as the recovery by the ink pressure circulation, the cleaning member 70 is washed (step S3). By this cleaning, thickening ink, foreign matter, etc. adhering to the cleaning member 70 are washed away together with the cleaning liquid.

Next, in step S4, the amount of the cleaning liquid remaining on the cleaning member 70 is appropriately reduced by sucking the cleaning liquid, so that the ability to collect ink, foreign matters, etc. is improved, and the cleaning effect of the manufacturing member 70 is improved. Can be increased. Further, by sucking the cleaning liquid, a negative pressure due to a capillary phenomenon is generated inside the porous member that is the cleaning member 70. By making this negative pressure larger than the negative pressure applied to the nozzles of the liquid ejection head, ink is drawn out from the nozzles during cleaning, so that the cleaning liquid is prevented from entering the liquid chamber. Further, since the ink absorbing ability inside the nozzle is also generated, it is possible to obtain the effect that the thickened ink inside the nozzle is removed at the same time.

Next, a drive signal is issued from the motor driver 23, the drive of the drive motor 5 is transmitted to the carriage 1 via the belt 4, the carriage 1 is driven, and the head reciprocates. Then, as shown in FIG. 7, when the carriage 1 passes the cleaning means 50, the cleaning member 70 sequentially wipes the ejection surface 22 to perform cleaning (step S5). In the present embodiment, wiping means wiping and cleaning the cleaning liquid, ink, foreign matter, etc. on the ejection surface.

As shown in FIG. 7, when the cleaning member 70 wipes the discharge port surface, since the cleaning member 70 is flexible, the cleaning member 70 falls in the same direction as the moving direction D of the carriage 1 and the wiping surface is weakly repulsed. 70B wipes the ejection surface 22, and cleaning is performed. Therefore, even if there is a step between the holder surface 102 and the ejection surface 22, it does not affect the cleaning effect.

Particularly, since the edge portion 70D of the cleaning member 70 enters into the concave portion of the holder portion, the holder surface 102 and the discharge surface 22
It is possible to clean up to the step between and.

From the print start detection position P ₀ detected by the print start detection sensor 34, ink droplets are ejected while traveling in the direction of arrow D, and an image is printed on the print width portion P of the print paper 6 (( Step S
6).

At the same time, the cleaning member is washed (step S7), and then the cleaning liquid is sucked (step S).
8) The cleaning ability of the cleaning member is restored. afterwards,
The carriage 1 is reversed and driven in the direction of arrow E to perform the preliminary ejection operation while passing through the preliminary ejection position (step S
9). Here, the preliminary discharge is performed on the liquid receiving member 32. Then, the print sheet 6 is conveyed in the direction of arrow F by the width of the print width member P.

Next, when the image printing continues (when a negative determination is made in step S10) and the 100-line printing is not completed (when a negative determination is made in step S11), the process returns to step S5. , Carriage 1
Reciprocates, and cleaning in reciprocation is performed as shown in FIG. 7 (step S5). At this time, since the wiping surface 70B of the cleaning member is wiped in the forward movement, the once-dirty wiping surface 70C does not wipe the ejection surface 22, so that the cleaning effect is not adversely affected and the cleaning effect is doubled. Has the effect of being enhanced.

On the other hand, when the image printing is completed (when a negative determination is made in step S10) or when the 100-line printing is completed (a positive determination is made in step S11), the ejection surface 22 of the head 2 is capped. It is capped and sealed by the means 20 (steps S12 and S13).

(Embodiment 1) In contrast to the above-described base technology, the life of the cleaning member 70 and the ejection surface 22 or the head 2 which are in sliding contact with each other is prevented from being shortened, or the recovery process is made more efficient, and further, the cleaning liquid and the waste liquid are used. In order to reduce the running cost and the running cost, the present embodiment employs the procedure shown in FIG. 8 in which appropriate processing is added to the procedure shown in FIG.

In the procedure shown in FIG. 8, immediately after the ink pressurizing and circulating operation (steps S1 and S2), the ejection surface is moved in the reciprocating direction with respect to the wiping blade (cleaning member) 70, and the ink is applied to the ejection surface after pressurization. A process for sufficiently wiping off a large amount of the remaining ink droplets is performed (step S5-a1).
Then, during the normal printing operation, when the print head returns to the home position direction (return path), only one surface of the wiping blade 70 is used to remove a small amount of ink droplets due to mist adhering to the head surface. (Step S5-a2). Further, along with this, step S6 to
Processing steps S6 'to S9' similar to S9 are added.

In this way, by changing and selecting the wiping direction of the wiping blade during printing, the frequency of sliding contact between the head 2 and the wiping plate 70 is maintained while maintaining the same wiping performance as compared with the base technology. Can be reduced, and the life of the head and the wiping blade can be improved. Further, since the wiping operation on the outward path is omitted, the production speed can be improved.

Further, as for the cleaning water for the wiping blade 70, it suffices to apply the cleaning water mainly on one side surface of the blade 70, and a sufficient cleaning effect can be obtained with a small amount of water as compared with the base technology.

(Second Embodiment) FIG. 9 shows a sequence of a second embodiment of the present invention.

In this sequence, immediately after the ink pressurization circulation operation and the like (steps S1 and S2), the ejection surface is moved at a low speed (for example, 43.3 mm) with respect to the wiping blade 70.
/ Sec) to wipe (reverse pass, one-side wipe) to sufficiently wipe off a large amount of ink droplets remaining on the ejection surface after pressurizing the ink (step S5-b1). During the normal printing operation, the ejection surface is wiped by the wiping blade 70.
On the other hand, the normal speed (return path, single-sided wiping, for example, 86.
5 mm / sec), and a process of removing a small amount of ink droplets due to mist adhering to the protruding surface is performed (step S5-b2).

As described above, by changing the wiping speed of the wiping blade during printing, it is possible to obtain the wiping performance equivalent to that of the first embodiment.

(Embodiment 3) FIG. 10 shows the sequence of the third embodiment of the present invention.

In this sequence, immediately after the operation such as ink pressurization circulation (steps S1 and S2), the wiping blade 70 penetrates the head holder surface by an amount d = 3 mm.
As shown in FIG. 4, a process is performed to wipe off a large amount of ink droplets remaining on the ejection surface after pressurizing the ink and to reliably remove the ink adhered in the liquid passage and in the vicinity of the ejection port (step S5-). C1).

During the normal printing operation, the amount of penetration between the wiping blade and the head holder surface is d = 5 mm.
As a (normal condition), wiping is performed and a process of removing a small amount of ink droplets due to mist attached to the protruding surface is performed (step S5-c2).

By changing the amount of penetration of the wiping blade in this way, the contact pressure and the wiping margin of the wiping blade can be changed. This makes it possible to have the wiping performance equivalent to that of the first embodiment.

(Fourth Embodiment) FIG. 11 shows a sequence of a fourth embodiment of the present invention.

In this sequence, immediately after the ink pressurization circulation operation and the like (steps S1 and S2), the pump suction time t ₁ of the wiping blade is set to, for example, 2 seconds (the washing time is strange), and the wiping blade is kept wet. In this state, the wiping operation is performed to sufficiently wipe off a large amount of ink droplets remaining on the ejection surface after pressurizing the ink and to reliably remove the ink adhered in the liquid passage and in the vicinity of the ejection port (step S5). -A1).

Then, during the normal printing operation, the pump suction time t ₂ (> t ₁ ) of the wiping blade 70 is set to, for example, 4 seconds, and the wiping blade 70 is slightly moistened to cause the wiping operation to adhere to the ejection surface. A process of removing a very small amount of ink droplets due to the generated mist is performed (step S5)
-A2).

By doing so, it is possible to cope with the wiping performance equal to or higher than that of the first embodiment, that is, the ink fixation after being left for a long time.

(Fifth Embodiment) FIG. 12 shows a sequence of a fifth embodiment of the present invention.

In this example, a procedure similar to that of the first example shown in FIG. 8 is adopted, but the process of step S13 is deleted, and instead of the process of step S11, during normal printing, The process of wiping the ejection surface is performed once every n rows (for example, n = 2) (step S11-2). In addition,
The value of n may be set according to the image to be printed. When printing an image with a high image print duty, the value of n is set small, and when the image print duty is low, the value of n is set large. Just do it.
The setting can be performed by, for example, verifying the content of the image data received from the device that supplies the image data to the device of FIG. 1, and the received image related to printing is not uniform. If there is a variation in print duty in one unit of image, the value of n may be changed appropriately.

The present invention is not limited to the embodiments described above, and various modifications can be made.

That is, the numerical values described in each of the above examples are merely examples, and appropriate numerical values can be adopted according to the device configuration and the like.

In each of the above examples, the case where the recovery process is performed at the start of printing and during printing has been described.
A recovery process, that is, positioning of the head to the home position, pressurization and circulation process, wiping, cleaning or suction of cleaning liquid, and resetting of the head to the home position may be executed when the device power is turned on. Good.

Further, such recovery processing may be activated by the operator operating a predetermined switch or the like as appropriate or in response to an instruction from the apparatus side.

In addition, an appropriate recovery process may be executed according to the image data to be printed.

(Embodiment 6) FIG. 13 shows an example of a recovery process according to such image data, in which recovery means is appropriately selected according to the image print duty to improve the production speed. It is a figure. That is, in this example, before the printing is started, the maximum print duty of the print head having the highest print duty than the image data is calculated, and the large recovery processing, the preliminary ejection processing, and the recovery processing by the wiping as described above are performed according to this value. The number of times each recovery means is inserted is determined. Here, the large recovery means a process (corresponding to steps S1 to S5) from a series of operations (including capping operation) from the ink pressure circulation operation to the wiping (double-sided reciprocating wiping) described above, and the preliminary ejection is As described above, it refers to a process of simultaneously ejecting from the ejection port group in a state where the cap or the absorber is opposed to the print head.

As shown in FIG. 13, when the maximum print duty is higher, the cleaning member 70 made of a porous material is used.
By frequent wiping operation by
The occurrence of non-wetting ejection can be suppressed. On the other hand, by performing the large recovery and the preliminary ejection more frequently as the maximum print duty is lower, the stable ejection operation from the initial ejection can be maintained for a long time.

(Others) In the present invention, when the ink jet printing method is adopted, among them, there is provided a means for generating thermal energy as the energy used for ejecting ink. An excellent effect is brought about by using a system that causes a change in ink state, that is, a bubble jet system print head and a printing device proposed by Canon Inc. According to this method, the density of the print is increased,
This is because high definition can be achieved.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the print information and causing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling occurs on the heat acting surface of the print head. This is effective because bubbles can be generated in the liquid (ink) corresponding to this drive signal one-to-one as a result. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124, which is an invention relating to the temperature rise rate of the heat acting surface, are adopted, more excellent printing can be performed.

As the structure of the print head, in addition to the combination of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, The present invention also includes a configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which the heat acting portion is arranged in a bending region. In addition, for multiple electrothermal converters,
Japanese Unexamined Patent Publication No. 59-123670, which discloses a configuration in which a common slit is used as the discharge portion of the electrothermal converter, and Japanese Laid-Open Patent Publication No. 59-63, which discloses a structure in which an opening for absorbing a pressure wave of thermal energy is associated with the discharge portion. The effects of the present invention are effective even with a configuration based on Japanese Patent Laid-Open No. 138461. That is, according to the present invention, regardless of the form of the print head, printing can be surely performed efficiently.

In addition, it goes without saying that the print head can be constructed according to the form of the printing apparatus, and in the case of the so-called line printer form, the ejection ports are arranged in a range corresponding to the width of the print medium. It should be one. Further, as the serial type print head as in the above example, the print head fixed to the apparatus main body or mounted on the apparatus main body enables electrical connection with the apparatus main body and supply of ink from the apparatus main body. The present invention is also effective when a replaceable chip type print head or a cartridge type print head in which an ink tank is integrally provided in the print head itself is used.

Further, it is preferable to add ejection recovery means for the print head, preliminary auxiliary means, etc. as the construction of the printing apparatus of the present invention because the effects of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suctioning means for the print head, preheating means for heating using an electrothermal converter or another heating element or a combination thereof, and printing Preliminary ejection means for performing another ejection can be mentioned.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself in the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, the ink is liquefied by applying heat energy according to the print signal,
The present invention is also applicable to the case of using an ink that has the property of being liquefied only when heat energy is applied, such as one that ejects liquid ink or one that has already started to solidify when it reaches the printing medium. . The ink in such a case is in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, it may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the present invention may be used as an image output terminal of information processing equipment such as a computer, or may be in the form of a copying apparatus combined with a reader or the like.

Next, as the ink-jet printing cloth, (1) the ink can be developed to a sufficient density,
(2) Ink dyeing rate is high, (3) Ink dries quickly on the cloth, (4) Irregular ink bleeding on the cloth is small, (5) In-apparatus It is required to have excellent performance such as excellent transportability. In order to satisfy these required performances, in the present invention, the fabric may be pretreated in advance, if necessary. For example, Japanese Unexamined Patent Publication (Kokai) No. 62-53492 discloses fabrics having an ink receiving layer, and Japanese Patent Publication No. 3-46589 proposes fabrics containing a reduction inhibitor and an alkaline substance. There is. Examples of such pretreatment include a treatment in which the cloth is made to contain a substance selected from alkaline substances, water-soluble polymers, synthetic polymers, water-soluble metal salts, urea and thiourea.

Examples of the alkaline substance include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide,
Examples thereof include amines such as mono-, di- and triethanolamine, and carbonic acid or alkali metal bicarbonate such as sodium carbonate, potassium carbonate and sodium bicarbonate. Furthermore, there are organic acid metal salts such as calcium acetate and barium acetate, and ammonia and ammonia compounds. Also, sodium trichloroacetate, which becomes an alkaline substance under steaming and dry heat, can be used. Particularly preferred alkaline substances are sodium carbonate and sodium bicarbonate used for dyeing reactive dyes.

As the water-soluble polymer, starch substances such as corn and wheat, cellulosic substances such as carboxymethyl cellulose, methyl cellulose and hydroxyethyl cellulose, sodium alginate, gum arabic,
Locust bean gum, tragacanth gum, guar gum,
Examples include polysaccharides such as tamarind seeds, protein substances such as gelatin and casein, and natural water-soluble polymers such as tannin-based substances and lignin-based substances.

Examples of synthetic polymers include polyvinyl alcohol compounds, polyethylene oxide compounds, acrylic acid water-soluble polymers, maleic anhydride water-soluble polymers, and the like. Among these, polysaccharide polymers and cellulose polymers are preferable.

Examples of the water-soluble metal salt include compounds such as halides of alkali metals and alkaline earth metals, which produce typical ionic crystals and have a pH of 4 to 10. As a typical example of such a compound, for example, in the case of an alkali metal, NaCl, Na ₂ S
O ₄ , KCl, CH ₃ COONa and the like can be mentioned, and as the alkaline earth metal, CaCl ₂ and Mg.
Cl _{2 and the} like can be mentioned. Of these, salts of Na, K and Ca are preferable.

The method of incorporating the above substances and the like into the cloth in the pretreatment is not particularly limited, and examples thereof include a dipping method, a pad method, a coating method and a spraying method which are usually carried out.

Further, the printing ink applied to the ink-jet printing cloth merely adheres to the cloth when it is applied to the cloth. Therefore, the step of fixing the pigment in the ink such as the dye to the fiber is subsequently performed. Is preferred. Such a fixing step may be a conventionally known method, for example, a steaming method, an HT steaming method, a thermofix method,
When a cloth which has been previously alkali-treated is not used, the alkali pad steam method, the alkali blotch steam method, the alkali shock method, the alkali cold fix method and the like can be mentioned. Further, the fixing step may or may not include a reaction step depending on the dye, and an example of the latter is one in which fibers are impregnated and are not physically separated. Any appropriate ink can be used as long as it has a required dye, and the ink is not limited to a dye and may include a pigment.

Further, the unreacted dye and the substances used for the pretreatment can be removed by washing after the above reaction fixing step according to a conventionally known method. In addition, it is preferable to use a conventional fixing treatment together with this cleaning.

The printed matter which has been subjected to the above-mentioned post-processing steps is then cut into a desired size, and the cut pieces are used for obtaining a final processed product such as sewing, bonding, welding, etc. After that, clothes such as dress, dray, tie, swimwear, duvet cover, sofa cover, handkerchief, curtain, etc. can be obtained. For the method of processing cloth by sewing etc. to make clothes and other daily necessities, please refer to known books such as "Latest Knit Sewing Manual" (published by Senyi Journal) and monthly magazine "Soen" (published by Bunka Publishing Bureau). Many are listed.

The medium for printing may be cloth, wall cloth, thread used for embroidery, wallpaper, paper, OHP film, etc. The cloth may be any material, weave or knit. Includes woven, non-woven and other fabrics.

[0086]

As described above, according to the present invention,
In a liquid ejecting apparatus that ejects a predetermined liquid using a liquid ejecting head, a wiping unit for wiping a liquid ejecting surface of the liquid ejecting head, and a unit for changing a wiping condition between the liquid ejecting surface and the wiping unit. By providing the above, it is possible to achieve a longer life of the head and the wiping means and an improvement in the production speed. Further, by providing the cleaning means of the wiping means, it is possible to enhance the cleaning effect of the liquid ejection surface of the head and perform stable ejection for a long period of time. Further, when the cleaning means discharges the cleaning liquid to the wiping means, the running cost can be reduced by reducing the cleaning liquid and the waste liquid by changing the wiping condition.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a configuration example of an inkjet printing apparatus as an embodiment of an apparatus to which the present invention is applied.

FIG. 2 is a schematic side view showing a configuration example of a head and an ink system.

FIG. 3 is a schematic diagram showing a configuration example of a recovery unit of this example including a wiping unit and a cleaning unit.

FIG. 4 is a schematic diagram showing a configuration example of a wiping means of the present example.

5 is a schematic plan view showing the configuration near the home position of FIG. 1. FIG.

FIG. 6 is a flowchart showing an example of a print sequence which is a premise of the present invention.

FIG. 7 is an explanatory diagram of a wiping operation.

FIG. 8 is a flowchart showing a print sequence according to the first embodiment of the present invention.

FIG. 9 is a flowchart showing a print sequence according to a second embodiment of the present invention.

FIG. 10 is a flowchart showing a print sequence according to a third embodiment of the present invention.

FIG. 11 is a flowchart showing a print sequence according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart showing a print sequence according to a fifth embodiment of the present invention.

FIG. 13 is a flowchart showing a print sequence according to a sixth embodiment of the present invention.

[Explanation of symbols]

 2 Liquid ejection head 50 Cleaning means 70 Cleaning member 70B Wiping surface 70C Wiping surface 75 Nozzle 76 Cleaning liquid supply tube 80 Tank 82 Suction means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location B41J 29/00 L (72) Inventor Toshiaki Mabuchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (11)

[Claims] 1. A liquid ejecting apparatus for ejecting a predetermined liquid using a liquid ejecting head, comprising: a wiping unit for wiping a surface of the liquid ejecting head on which the liquid is ejected; and the liquid ejecting by the wiping unit. And a means for changing the wiping condition of the surface. 2. The apparatus according to claim 1, further comprising means for changing the wiping condition during the operation of the liquid ejecting apparatus.
The liquid ejecting apparatus according to. 3. The cleaning device according to claim 1, further comprising a cleaning device for cleaning the wiping device, the cleaning device having a cleaning liquid discharging device for discharging a cleaning liquid to the wiping device. The liquid ejection device described. 4. The liquid ejecting apparatus according to claim 1, wherein the purifying unit has a liquid sucking unit for sucking the liquid from the wiping unit. 5. The liquid ejecting apparatus according to claim 1, wherein the changing wiping condition is a relative wiping direction of the wiping unit with respect to the liquid ejecting head. 6. The liquid ejecting apparatus according to claim 1, wherein the changing wiping condition is a relative wiping speed between the wiping unit and the liquid ejecting head. 7. The liquid ejecting apparatus according to claim 1, wherein the changing wiping condition is a relative amount of penetration of the wiping means with respect to the liquid ejecting head. 8. The liquid ejecting apparatus according to claim 3, wherein the changing wiping condition is a cleaning liquid content of the wiping unit. 9. The liquid ejecting apparatus according to claim 1, wherein the changing wiping condition is the number of times of contact between the wiping unit and the liquid ejecting surface. 10. As a recovery process for maintaining a good ejection state of the liquid ejection head, a unit that performs a process using the wiping unit, and a process that uses the wiping unit and pressurizes an ink supply system. And means for ejecting ink from the liquid ejection head,
10. The liquid ejecting apparatus according to claim 1, wherein the processing conditions of the means for performing these processes are changed in accordance with the image data. 11. The liquid ejection head has an element for generating thermal energy as energy used for ejecting the liquid.
0. The liquid ejection device according to any one of 0.