JP3067829B2 - Recovery method for inkjet recording apparatus and inkjet recording apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering an ink jet recording head and an ink jet recording apparatus using an ink jet recording head which is detachable from an apparatus main body.

[0002]

2. Description of the Related Art In a conventional ink jet recording head or apparatus, a thermal energy recording system utilizing film boiling has a particularly excellent recording characteristic and recording quality as compared with a system utilizing a piezoelectric element, and uses light energy and the like. It has been put to practical use as being superior to other thermal energy recordings.

However, in such a recording head and a recording apparatus,
Since liquid ink is used as the recording agent, the ink may thicken or solidify, and in order to eliminate the inconvenience caused by this, a unique ink jet recording device that is not seen in other recording devices In other words, there is provided a means for refreshing the inside of the liquid path and for making the ejection port forming surface in a good state, that is, a so-called ejection recovery system of the recording head.

There are various types of these ejection recovery systems. First, a device for refreshing the inside of a liquid path is driven to drive an ejection energy generating element to eject ink to a predetermined ink receiving medium except during recording. (Preliminary ejection or idle ejection).

A patent disclosing this is British Patent No.
No. 2,169,855 can be mentioned. This patent also discloses that the ink is preliminarily heated and then preliminarily ejected after that.

Further, there is a type in which ink is forcibly discharged from a discharge port by applying a predetermined pressure to a liquid path, for example, by pressurizing an ink supply system or performing suction from an ink discharge port. .

A typical patent that discloses this is US Pat. No. 4,600,931. This suction recovery is not always performed, but is performed immediately before a situation where recording failure occurs or in a non-discharge state. There have been many applications for the invention of suction recovery, and among them, there is also known an invention that switches between a large recovery that increases suction conditions and a normal recovery that performs normal suction.

In order to prevent the deflection of the ejection direction by refreshing the ejection port forming surface, a wiping member that contacts the ejection port forming surface is provided, and the ink adhering to the vicinity of the ejection port is formed by relatively moving the wiping members. Some wipe (drop) dust and dust.

[0009]

SUMMARY OF THE INVENTION The present inventors have studied the conventional recovery means, and found that the preliminary ejection condition is changed in an environmental change during recording (including a head temperature, an ambient temperature, and steps in a sequence). Is effective, and suction and forced discharge by a pressure pump are usually effective,
The following problems have been found.

In other words, there have been cases where a high level of recovery cannot be achieved even if a larger amount of ink is consumed and a long time is taken. This is a problem particularly at the time of forcible discharge by suction or pressurization, and is caused by wasting of ink without applying a uniform suction force or pressing force to all of the plurality of ejection openings. In particular, it was found that increasing the size of the pump was not so effective in order to increase the recovery power, and that the amount of ink loss was rather large. Increasing the number of times causes a problem that the time spent for the recovery process becomes longer and the recording throughput decreases. These are remarkable in the recovery processing under a low temperature environment.

An object of the present invention is to provide a method of recovering an ink jet recording head which can efficiently improve the recovery capability of a given forced recovery means and achieve a reliable recovery without increasing the size of the apparatus, and implement the method. In providing the equipment.

Another object of the present invention is to provide a recovery method and a printing apparatus which can execute a reliable recovery process even under the influence of an absorber which is a negative pressure generating source in an ink storage section supplied to a print head. is there.

Another object of the present invention is to provide a recovery method and a recording apparatus in which the degree of recovery is superior to that of the prior art, the processing time can be shortened, and the amount of ink loss can be optimally reduced. .

Still another object of the present invention is to
An object of the present invention is to provide a recovery method and a recording apparatus that can obtain efficient suction from the start of the recovery process without increasing the size of a mechanism such as a tube pump.

[0015]

According to the present invention, there is provided a recording head having an energy generating element for generating energy used for discharging ink from a discharge port, and the recording head having the same. In a recovery processing method for an ink jet recording apparatus, comprising: a cap for covering a discharge port; and a suction unit for performing suction from the discharge port when the cap covers the discharge port. A large recovery step of performing suction from the discharge port by the suction unit while covering the outlet, and driving the energy generating element to discharge ink from the discharge port; and covering the discharge port with the cap. Suction from the discharge port by the suction means in a state where the suction force is smaller than the suction force in the large recovery step. And small recovery step of performing ink ejection from perform the discharge port, characterized in that it comprises a.

Here, the energy generating element may be a heating element, and in the large recovery step, a drive signal for forming a bubble in the ink may be supplied to the heating element. A plurality of the drive signals may be supplied to the heating element to perform the ink ejection a plurality of times. The large recovery step may be performed after the apparatus has been stopped for a long period of time, and the large recovery step may be performed when the ink discharge state does not become good even after performing the recovery processing on the printhead. The small recovery step may be performed immediately after a predetermined amount of recording operation.

According to a seventh aspect of the present invention, there is provided a print head having an energy generating element for generating energy used for discharging ink from a discharge port, and a cap for covering the discharge port of the print head. And a suction unit for performing suction from the discharge port when the cap covers the discharge port, a heating step of heating ink in the recording head in a recovery processing method of the ink jet recording apparatus having: After the heating step, while the cap covers the discharge port, suction is performed from the discharge port by the suction unit, and the energy generating element is driven to discharge ink from the discharge port. And suctioning from the discharge port by the suction means with the cap covering the discharge port after the heating step. Characterized in that it comprises a small recovery process performs only suction exerting a small suction force than the suction force ejects ink from the discharge port in.

Here, the energy generating element may be a heating element, and in the large recovery step, a driving signal for forming a bubble in the ink may be supplied to the heating element. In the large recovery step, a plurality of the drive signals may be supplied to the heating element to perform a plurality of ink ejections.

The invention according to claim 10 is an ink jet recording apparatus for performing recording by a recording head having an energy generating element for generating energy used for discharging ink from a discharge port. A cap for covering the discharge port, a suction means for performing suction from the discharge port when the cap covers the discharge port, and the suction means for covering the discharge port with the cap. While performing suction from the discharge port, a large recovery process in which the energy generating element is driven to discharge ink from the discharge port, or the suction unit covers the discharge port in a state where the discharge port is covered by the cap. Only the suction that applies a suction force smaller than the suction force in the large recovery process is performed, and the ink that is ejected from the ejection port is small. Characterized in that it comprises a control unit to perform the recovery process.

Here, the large recovery process may be performed after the apparatus has been stopped for a long period of time, and the large recovery process may be performed when the ink discharge state does not become good even after performing the recovery process on the recording head. You may. The small recovery process may be performed immediately after a predetermined amount of recording operation. The control unit may drive the energy generating element so that the ink is heated prior to the large recovery processing and the small recovery processing.

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

According to the present invention, in a recovery processing method for an ink jet recording apparatus, ink is ejected from a discharge port by driving an energy generating element while performing suction from the discharge port with the discharge section covered by a cap. Performing a large recovery step and performing suction from the discharge port by the suction means with the cap covering the discharge port, and performing only suction to apply a suction force smaller than the suction force in the large recovery step. Including a small recovery step of discharging ink, bubbles inside the discharge port are removed, and ink is more slowly sucked from the discharge port in the small recovery step than in the large recovery step, and the flow of the ink is stable. Will be done.
Therefore, when the suction force is large and the flow of the ink is not stable, turbulence and fine bubbles which are not removed by the vortex are reliably eliminated. In the small recovery step, the amount of ink to be sucked is also reduced, so that unnecessary consumption of ink is avoided.

[0027]

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

(1) Cartridge First, FIG. 1 shows an example of the configuration of a cartridge C that can be mounted on a carriage (described later with reference to FIG. 3) of the ink jet recording apparatus according to the present embodiment. The cartridge C according to the present example has an ink tank section 80 having an ink absorber (sponge or the like) therein and a recording head 86 below, and further receives a signal for driving the recording head 86 and the like. In addition, a head-side connector 85 for outputting the detection of the remaining amount of ink is provided at a position aligned with the ink tank unit 80. Therefore, when the cartridge C is loaded on a carriage described later, the height H can be kept low. Further, by reducing the thickness W of the cartridge in the scanning direction, the cartridge C can be formed as described later with reference to FIG.
It is possible to make the carriage small when arranging them side by side.

Reference numeral 83 denotes a connector cover formed integrally with the outer wall of the tank to prevent accidental contact with the connector 85. Reference numeral 81 denotes a positioning portion, which is a contact surface in two directions.
81a and 81b are formed. By providing a sufficient distance between these positioning surfaces and a positioning abutting surface provided on the recording head 86, the slope 84 formed by a push pin described later is used.
By pressurizing the section, the recording head can be reliably positioned and fixed. Reference numeral 82 denotes a knob, which is used when the cartridge C is attached to and detached from the loading section. Reference numeral 82a denotes an atmosphere communication hole provided on the front of the knob 82 for communicating the inside of the ink tank section 80 with the atmosphere. Reference numeral 82a denotes a cutout portion, and reference numeral 83b denotes a guide, both of which serve as guides for loading the cartridge C into the loading portion.

The recording head 86 according to the present embodiment has a plurality of discharge ports opened on the bottom side in the figure, and discharge energy generation for generating energy used for ink discharge in a liquid passage portion communicating with the discharge ports. An element is arranged. As this discharge energy generating element, it is preferable to use a thermal energy generating element because the discharge ports or liquid paths can be highly integrated.

FIGS. 2A and 2B are a front view and a side sectional view, respectively, as seen from the front of the recording head 86 in the ejection direction.

2A and 2B, reference numeral 101 denotes a base plate of the recording head 86, which is formed of Al. On the substrate 101, a substrate (heater board) 102 made of Si or the like is bonded. On the surface of the heater board 102, an electrothermal converter (not shown) as a thermal energy generating element, a diode as a functional element for driving the electrothermal converter, and the like are formed. Reference numeral 103 denotes an orifice plate (ejection port forming member), which is integrally formed with a top plate 103A provided with a groove for forming an ink liquid chamber.

The formation of the discharge ports in the orifice plate 103 can be performed with high precision by, for example, excimer laser light irradiation or a photo-etching process, whereby a highly accurate shape can be obtained over the plurality of discharge ports. Also, this orifice plate 103
When a plurality of different materials are exposed on the discharge port forming surface, this is also used to prevent deflection of the discharge direction caused by a difference in wettability between these materials.

Reference numeral 104 denotes a filter, and a chip tank 105
Is provided at an ink supply port extending from the ink supply port to the common liquid chamber. The filter 104 removes impurities, dust, and the like of the ink flowing as indicated by arrows in the figure. The ink that has passed through the filter 104 flows into the common liquid chamber 106, and is supplied to each of the plurality of ink liquid paths 107 that communicate with the liquid chamber in accordance with the ejection. Reference numeral 109 denotes a pressing member that presses the orifice plate 103 with its elastic force or the like and makes the orifice plate 103 come into close contact with an opening surface (in particular, the end surface of the heater board 102). In this example, the holding member 10
9 is made of SUS (stainless steel).

In the above configuration, ink is supplied from the ink tank unit 80 integrated with the recording head 86 to the chip tank 105, and thereafter the ink flows as shown by the arrows. First, dust and impurities in the ink are removed by passing through the filter 104, and the ink reaches the common liquid chamber 106 and is guided to the liquid path 107 therefrom. Then, by driving the electrothermal transducer disposed in the liquid path 107, bubbles are generated in the ink, and the ink is discharged through the discharge port 108 by the change in the state of the bubbles.

(2) Carriage FIG. 3 is a plan view showing a configuration example around the carriage of the ink jet recording apparatus to which the cartridge C shown in FIG. 1 can be mounted. The figure shows an example in which four cartridges C1, C2, C3, and C4 (each containing ink of a different color, for example, yellow, magenta, cyan, and black, etc.) are positioned and loaded on the carriage 2. ing.

Four push pins 10 (push pins A to D) are engaged with the connector holder 40 as a holding member, and are attached to the left in FIG. 3 by springs 10a (springs A to D). It is being rushed. Here, a connector holder as a holding member
40 is engaged with the link 21 (link I / link II) via the shaft 20 (axis I / axis II), and furthermore, the rotational operation (clockwise / counterclockwise) of the operating lever 7 engaged with this link 21 3), can be moved in the left-right direction in FIG. 3, can be moved rightward to release the pressurization, and the cartridge can be replaced,
On the other hand, it is configured to move to the left to receive the loading of the cartridge.

When the operating lever 7 is rotated clockwise about the shaft 9, the holder 40 advances, the pins 10 engage with the cartridge C, and the cartridge C is loaded into the loading section. The tip portions 10b of the push pins 10 abut against the abutting surfaces 1d of the four cartridges C, respectively, and press the cartridges. Further, the outer peripheral surface 10c of the push pin 10 comes into contact with the abutment surface 2S of the carriage 2 and has a structure in which a thrust force generated in a direction perpendicular to the push pin axis is generated independently. Accordingly, the holding member 40 receives only the reaction force of the springs 10a (springs A to D) and does not act on the thrust force. Therefore, even when a plurality of cartridges are simultaneously released, the release lever 7 can be operated with a small operation force. The user can operate it to perform the detaching operation.

Next, the head connector 85 on the cartridge C side
And a mechanism or operation for fitting and disengaging with a connector (body connector) 6 provided on the main body side to be engaged with this.

When the main body connector 6 is inserted into the head connector 85 (the engagement shaft 6a integral with the main body connector 6 is engaged with the slit-shaped engagement of the connector holder 40 by the elastic force of the tension spring 41 (see FIG. 4). When the lever 7 is operated, the main body connector 6 and the connector holder 40 move as a unit when the lever 7 is operated. Then, the head connector 85 and the main body connector 6 meet, and are guided (guided) by the slope (not shown) of the main body connector 6 so that the main body connector 6 is fitted (coupled) with the head connector 85. Thereafter, the connector holder 40 moves rightward by a predetermined distance toward the operation rail 11 (this movement is performed by rotation of the lever 7). Here, the predetermined distance is a moving distance of the connector holder 40 for changing the main body connector 6 from the positioning state to the movable (released) state.

The main connector 6 is a head connector.
The main body connector 6 is released from the connector holder 40 because the main body connector 85 and the tension spring 41 are coupled with each other with a stronger force. That is, the engagement is released. Therefore, when the main body connector 6 and the head connector 85 are fitted (coupled), the main body connector 6 is released from the connector holder 40, so that the cartridge C is positioned with respect to the carriage 2 only by the pressing force of the push pin 10. Thus, accurate positioning of the recording head 86 with respect to the carriage 2 is ensured.

Next, when the cartridge C is to be removed (released), the lever 7 is rotated counterclockwise from the upright position to the horizontal position. Then, although the engagement shaft 6a is coupled with the head connector 85 with a strong force, the connector holder
As 40 moves to the right, the large diameter side surface of the engagement hole 40a abuts against the engagement shaft 6a, and the main body connector 6 is detached from the head connector 8 while pushing the engagement shaft 6a in the depth direction in FIG. (Release). At the same time, push pin 10 is also a connector holder
It moves together with 40 and moves away from the recording head 86.

(3) Outline of Recording Apparatus In FIGS. 3 to 5, reference numeral 11 denotes a scanning rail which extends in the main scanning direction of the carriage 2 and slidably supports the carriage 2, 11a denotes a bearing, and 51 denotes a connector. Intermediate cartridge C
A flexible cable 52 for transmitting and receiving various signals to and from the belt 52 is a belt for transmitting a driving force for reciprocating the carriage 2. Also, 17,18 and 15,16 are
A pair of rollers 50 arranged before and after the recording position of the recording head 86 for nipping and transporting the recording medium, and a platen 50 for regulating the recording surface of the recording medium flat.

FIG. 4 is a schematic diagram of a recording apparatus such as a printer or a copying machine or a facsimile to which the above configuration is applied.

The recording apparatus main body 1000 has a cover 1101 that can be opened and closed at the front of the operation side. When the cover 1101 is opened around the rotation center axis, the inside of the main body is opened. By this opening, the above-described rotation operation of the lever 7 becomes possible, and the cartridge C1 to C4 can be attached to and detached from the apparatus main body. The lever 7 indicated by the solid line in the figure is the first lever.
A position where the illustrated cartridge can be mounted is shown. In this position, the cover 1101 is prevented from moving to the closed state. In the drawing, the cartridges indicated by broken lines indicate those in the mounting operation, and the cartridges indicated by solid lines are positioned in the apparatus main body at predetermined positions where recording is possible. At this time, the ejection port forming surface of the recording head 86 of the cartridge faces parallel to the guide surface of the platen 50, and the protruding recording head portion protrudes downward from the carriage and is located between the recording medium transport rollers 16, 18. ing. Reference numeral 1102 denotes a flexible sheet of an electric wiring portion, and reference numeral 12 denotes a rail for supporting and guiding the carriage 2 together with the rail 11 described above.

The connector holder 40 is shown in a state after the cartridge is mounted and the lever 7 is in a broken line state to complete the fixing of the cartridge to the carriage. Reference numerals 20, 202 denote shafts provided on both sides with respect to the direction of relative movement of the connector holder 40 with respect to the carriage, and are arranged at the same position at the same position. This shaft has a cylindrical shape that is movable within two elongated holes having its central major axis on a straight line on both sides of the carriage. In the figure, the shafts 20 and 202 correspond to the levers 7 shown by solid lines at positions shown by solid lines. These shafts 20 and 202 make the translation of the connector holder more reliable. In this example, since the shafts 20 and 202 are provided other than the connector main body and are disposed near and above the recording head positioning push pin 10, the positional accuracy of the recording head positioning push pin 10 is improved. In addition, the same axis as the shafts 20 and 202 should be provided on the connector body to stabilize the parallel movement of the connector body, and to give the degree of freedom in the front-rear direction and in the left-right direction by the gap with the side plate after the connector is connected. Can also. In this embodiment, the positioning of the positioning push pin 10 becomes dominant only on the shaft 20 without fixing the shaft 202 in the front-rear direction after the connector body has connected the long hole for the shaft 202 with the connector. Is preferable.

(4) Outline of Recovery System Unit Next, the recovery system unit according to this embodiment will be described.

FIG. 5 is a schematic diagram for explaining the arrangement portion and schematic configuration of the recovery system unit. In this example, the recovery system unit is disposed on the home position side.

In the recovery system unit, reference numeral 300 denotes a cap unit provided for each of the plurality of cartridges C having the recording heads 86. As shown in FIG. It can slide and can move up and down. When the carriage 2 is at the home position, the carriage 2 is joined to the recording head unit 86 and capped.

In the recovery unit, 401 and 402 are first and second blades as wiping members, respectively, and 403 is a blade cleaner made of, for example, an absorber for cleaning the first blade 401. In the present embodiment, the first blade 401 is held by a blade elevating mechanism driven by the movement of the carriage 2, whereby the exposed surface of the orifice plate 103 of the ejection port forming surface of the recording head 86 is moved. It can be set to a position protruding (upward) for wiping and a position retracted (downward) so as not to interfere therewith. In this example, it is assumed that the recording head 86 is mounted so that the portion having the width b in FIG. 2A is located on the left side in FIG. 7, and when the carriage 2 moves to the right side from the left side in FIG. Wiping by the first blade 401 is performed. As a result, the exposed surface of the orifice plate 103 is changed from a narrow side (part of width a) to a wide part (part of width b) defined by the arrangement positions of the discharge ports shown in FIG. The wiping is performed only for ()). As for the second blade 402, the ejection port forming surface of the recording head 86 which is not wiped by the first blade 401, that is, the surface of the pressing member 109 on both sides of the exposed orifice plate surface in FIG. 2A is wiped. It is fixed in position.

Further, in the recovery system unit, reference numeral 500 denotes a pump unit which communicates with the cap unit 300. The pump unit 500 is used to generate a negative pressure for a suction process or the like performed by joining the recording head 86 to the cap unit 300.

(4.1) Cap Unit FIGS. 6 and 7 are a plan view and a side view showing a detailed configuration example of the recovery system unit, respectively.

First, the cap unit 300 has a recording head
86, a cap 302 closely contacting the discharge port 86, a holder 303 for supporting the cap, an absorber 306 for receiving ink during idle discharge processing and suction processing, and a suction tube 304 for sucking the received ink. And a connection tube 305 and the like connected to the pump unit 500. The same number (four in this example) of cap units 300 are provided at positions corresponding to the respective cartridges C, and are supported by the cap holder 330.

Reference numerals 332 and 334 denote pins protruding from the cap holder 330. The pins 332 and 334 are provided on the fixed recovery system base 350 and engage with cam grooves (not shown) for vertically guiding the cap holder 330. Things. Spring 36
0 applies a biasing force so that the cap holder is held at the right end position and the lowered position.

As shown in FIG. 12, reference numeral 342 in FIG. 6 denotes an engagement portion which is raised from the cap holder 330 and engages with the carriage 2 at a position on the left side of the start position. When the carriage 2 moves leftward from the start position, the cap holder 330 moves against the urging force of the spring 360 by the engaging portion 342. At this time, the cap holder 330 is guided and is displaced leftward and upward. Therefore, the cap 302 comes into close contact with the periphery of the ejection port of the recording head 86, and capping is performed. The position of the carriage 2 when the capping is performed is set as a home position.

Next, the configuration and operation of the cap unit 300 according to this embodiment will be described with reference to FIG. In the drawing, the absorber 306 is omitted.

The cap 302 is made of an elastic material, and the holder 30
3 and a tubular structure 30 attached to the fixed portion 302a.
An edge portion 302c for stretching the 2b is formed, and these are integrally molded.

The cap 302 can be formed from an elastic material such as silicon rubber, butyl rubber, or the like.

The ability of the cap 302 to follow the ejection port arrangement surface of the recording head can be improved by making the thickness of the portion t (edge 302c) shown in the figure as thin as possible. The thickness t of the edge 302c is preferably 0.4 mm or more,
It is desirable that it be 1 mm or less.

With such a structure, the tubular structure 302b of the cap 302 has elasticity in the contact direction of the discharge port sealing means with the discharge port arrangement surface, and the elastic member is used to arrange the discharge port of the cap. Eco rise to the surface is achieved. The contact of the cap unit 300 with the discharge port forming surface is as follows.
This is performed by moving the cap holder 330 with respect to the recovery system base 350. At this time, if the rear end side of the connection tube 304 is opened to the atmosphere and the contact is made, even if the space inside the cap is reduced, the inside of the cap is kept at the atmospheric pressure, and the ink meniscus inside the discharge port does not recede. .

Next, when the cap is detached, the space inside the cap is greatly reduced when the cap 302 is in contact with the recording head 86. Negative pressure effect)
Therefore, it is easier to hold the ink in the cap.
That is, when the cap is detached from the recording head, the contracted cap returns to the original state. Further, when the cap is detached, the inside of the cap changes from the negative pressure condition to the atmospheric pressure state, so that the ink is prevented from spilling out of the cap, and the ink can be kept in the cap. This effect can be obtained more effectively by setting a space wider than the inner diameter of the cap immediately below the cap of the holder 303.

(4.2) Blade Elevation Mechanism and the Like Next, the elevation mechanism of the first blade 401 will be described.

Referring again to FIG. 7, reference numeral 410 denotes a vertically movable blade holder, on which a first blade 401 is mounted by a mounting tool 411. Reference numeral 412 denotes a holder return spring for urging the blade holder 410 toward the lowered position.

430 is a pin protruding from the blade holder 410
The lock lever is rotatable about 414 and locks the blade holder 410 at its raised position by engaging with the upper surface of the stopper 432, and is urged upward by a spring in FIG. I have. Also,
In the state shown in the figure, the portion 41 protruding from the blade holder 410 is shown.
6 and held in the position shown.

Reference numeral 440 denotes a release lever which is rotatable around a pin 418 protruding from the blade holder 410 and releases the lock state of the lock lever 430 at the raised position of the blade holder 410. By doing so, the lock is released. That is, the release lever 440 is provided with a pin 442 that engages with the lock lever 430, and when the release lever 440 rotates around the pin 418, the pin 442 rotates the lock lever 430 around the pin 414. Then, the engagement between the lock lever 430 and the upper surface of the stopper (not shown) is released.

These mechanisms are for raising the driving force blade holder 410 from a cam (not shown) that operates in accordance with the movement of the carriage 2 and are not limiting to the present invention.

FIG. 9 is a side sectional view showing details when the blade 401 performs wiping. As shown in FIG. 9, in this example, only the width from the discharge port to the step is narrower to wider. It is wiped. That is, wiping is performed in a direction in which the discharge port arrangement is deviated in the orifice plate 103. By doing so, even if the vicinity of the discharge port gets wet or dust adheres, it is possible to reproduce a clean discharge port surface by wiping and maintain a good discharge state.

Conversely, if the distance from the ejection port to the step is wiped from the widest to the narrower, the remaining ink or dust remaining on the narrower step will remain, and as a result the distance will be short. It is not preferable because the orifice may be blocked.

In this embodiment, the first blade is appropriately moved up and down as described above, so that the distance to the step portion is wiped from a narrow side to a wide side. Even in the worst case, the ink or dust is located at the position of the discharge port 8. Since the state is not reached, it is possible to maintain a stable discharge state without affecting the discharge port.

By the way, in this example, since the wiping direction is defined as shown in FIG. 9, if no consideration is given to the wiping speed, that is, the moving speed of the carriage 2, the material and shape of the blade 401 Due to various factors (elastic coefficient and the like) determined by the above-mentioned factors, a problem may occur in the ability to follow the unevenness of the discharge port forming surface. That is, the first blade 401 cannot follow the step, and when this is restored, there is a problem that the first blade 401 has already jumped over the discharge port 108. Therefore, in this example, in consideration of these factors, the carriage 2 is moved at a slower speed during wiping than during normal scanning, so that the vicinity of the discharge port is reliably wiped.

FIGS. 10A and 10B are views for explaining the manner of cleaning the blade 401. FIG. As described above, as the cap unit 300 slides, the blade 401
Rises (FIG. 9A), and then wiping is performed as the carriage 2 moves to the right. At this time, in this example, the ink that has been wiped and received by the blade 401 flows only along the surface of the blade 401 and does not drip into the apparatus.

When the carriage 2 moves from the right, the blade 401 descends as shown in FIG. Blade cleaner 403 is the cap unit 3
Even when the cap unit 300 is attached to the blade 00, the cap unit 300 has already returned to its original position, and is in contact with the blade 401. Therefore, as the blade 401 descends, all the ink and the like adhering to the surface of the blade 401 are received by the cleaner 403 in the form of an absorber, so that the blade 401 is reliably wiped.

(4.3) Pump Unit The pump unit 500 will be described with reference to FIGS.

Here, reference numeral 502 denotes a regulating surface of a recovery system base provided in a semi-cylindrical surface shape, and a tube 304 configured as a flexible member is crawled at least on the regulating surface. Reference numeral 510 denotes a pressure roller which rotates around the pump shaft 504 while pressing the tube 304 against the regulating surface 50. The pressure roller 510 rotates while crushing the tube 304 in the direction of the arrow in FIG. A pressure is generated to suction ink from the discharge port.

Reference numeral 520 denotes a guide roller for rotating the pressure roller 510, which is supported by a pump shaft 504. 52
Reference numeral 2 denotes a holder for attaching the shaft 512 of the pressure roller 510 to the guide roller 520. Numeral 524 is a guide partition provided integrally with the guide roller 520 to suppress the decoy of the group of tubes 304 and separate them separately. A position cam 526 is integrated with the guide roller 520 and receives a driving force for rotating the guide roller 520. Reference numeral 528 denotes a pump driving gear, which has a gear meshing with a gear 15A provided on the shaft of the recording medium conveying (sub-scanning) roller 15 and a gear integrally provided on the position cam 526. That is, in this example, the driving force for driving the pump (rotation of the pressure roller) is received from the roller 15.

Reference numeral 530 denotes a leaf switch as a detecting means provided for recognizing the roller position, which is switched by a cam 532 which rotates around the pump shaft 504 together with the guide roller 520.

(5) Sequence of Recording Apparatus (5.1) Position Setting of Pressure Roller First, the setting of the position of the pressure roller of the pump unit 500 for applying a suction force to forcibly discharge the ink from the recording head 86 will be described. I do.

FIG. 11 is an explanatory view of this, in which (K) to (M) indicate the set positions of the pressure roller 510. In the figure, the counterclockwise direction (direction in which suction is performed) is “+” and the clockwise direction is “−”.

First, at the position (K), the pressure roller 510 is
4 is not crushed. In this state, even during capping, the inside of the cap or the ink suction system communicates with the atmosphere. At positions (L) and (M), the pressure roller 510 is
This is the position where the tube 304 is stopped after squeezing while rotating the tube 304 along the 502. In these set positions, the tube 304 is crushed, so there is no inside of the cap at the time of capping and the suction system is sealed from the atmosphere. .

In the present embodiment, there are two types of recovery processing by ink suction. One is to operate an appropriate operation means such as a switch after the apparatus has been stopped for a relatively long period of time, or when the ink ejection state is not good even by other recovery processing such as mere idle ejection, wiping or the like.
Or it is done automatically. At this time, since the ink is hardly discharged due to viscosity increase or the like, a large suction force is applied to the discharge port in the cap, that is, the ink is rapidly discharged by increasing the flow velocity. At the same time, the idle discharge operation is executed (hereinafter, this is referred to as a large recovery or recovery combined period).

The other is to improve the ejection state by refreshing or cooling immediately after a predetermined amount of recording operation. In particular, in an apparatus such as this example that uses heat energy as the ejection energy, the ink temperature is relatively high at this time, the viscosity is low, and the ink is relatively easily discharged. A smaller suction force is applied to discharge ink (hereinafter, this is referred to as small recovery).

At the time of the large recovery and the small recovery, in this example, the pressurized roller 510 rotated by +
(L) and M are set and held for a predetermined time. The acting suction force and suction amount are determined by the increase in the internal volume of the ink suction system, that is, the internal volume corresponding to the length from the position where the + rotated pressure roller 510 starts to crush the tube 304 to the stop position. When the motor is stopped at the position (M), the suction force is smaller than that at the position (L). according to this,
At the time of the small recovery, the ink is drawn more gently from the ejection port than at the time of the large recovery. Therefore, the state of the flow is stable, and fine bubbles and the like that may exist inside the discharge port, that is, fine bubbles and the like that cannot be removed due to turbulence and vortex generation when the suction force is large and the flow state is not stable Can also be reliably eliminated. In addition, since the amount of ink sucked at this time is also small, the ink is not consumed more than necessary.

In order to mainly reduce the ink consumption, the position (L) may be set at the time of a small recovery, and the time for stopping here may be shorter than that at the time of the large recovery. In addition, if the removal of fine air bubbles or the like is to be mainly ensured, the rotation speed of the pressure roller 510 may be reduced at the time of a small recovery so that the ink is sucked gently. Further, in this case, if the stop position is appropriately determined, reduction in ink consumption can be achieved.

As a means for forcibly discharging the ink, another type of suction pump may be used, or an ink supply system reaching the discharge port may be pressurized. The use of the unit 500 facilitates the above control or adjustment.

(5.2) Position Setting of Carriage The position setting mode of the carriage 2 will be described with reference to FIG. (A) to (D) in the drawing are positions based on the head located closest to the recording area.

First, FIG. 7A shows the reversing position at the time of wiping. Further, in this example, this position is a position set when capping is performed or when the blade 401 is raised. In this example, since the operations for capping and projecting the blade are performed in accordance with the movement of the carriage 2, it is necessary to transmit a certain amount of force from the carriage 2. Therefore, by setting the carriage 2 at an appropriate position (A) and moving the carriage 2 from this position and utilizing its inertia, the motor as the driving source of the carriage 2 is not enlarged and the driving power is not increased. ,
A necessary and sufficient amount of driving force for driving the above mechanism is obtained.

Next, the position (B) in FIG. 9B shows the start position of the recording operation and the start position which is the reverse position during the recording operation. At this time, each head 86 and each cap 300 face each other.
330 and blade holder 410 are not driven, so cap 300 is in a position spaced from head 86 and blade 401 is not raised. The idle discharge is performed at this position.

Next, a position (C) shown in FIG. 10C is a position where the raising of the blade holder 410 is started. When capping or wiping is performed, this position is passed or set to this position. The position (D) in FIG. 11D is a position where the cap holder 330 is raised and capping is performed, and a large recovery or a small recovery is performed at this position, and a standby state when recording is stopped is performed. Will be

(5.3) Summary of Operation Sequence FIGS. 13A to 13E summarize the operation sequence of this example. In these, "1" is a column indicating the position of the pressure roller 510, and "2" is a column indicating the position of the carriage 2. (K) to (M) are the roller positions shown in FIG. 11, and (A) to (M).
(D) is the same as the carriage position shown in FIGS. 12 (a) to (d).

FIG. 11A shows an initial process after the power is turned on, and the pressure roller and the position of the carriage are initialized. FIG. 7B shows a state in which a recording start command is given by pressing a copy button or the like, and thereafter, the recording medium is fed by cassette paper feeding or manual paper feeding. FIG. 9C shows a process at the time of wiping or idle discharge performed at an appropriate timing (for example, every 5 to 10 lines of print scan) during the printing process. FIG. 9D shows a recording end process including a small recovery process which is performed immediately after the end of a predetermined amount (recording on a recording medium for one page in this example). FIG. 11E shows the processing at the time of the large recovery.

The details will be described with reference to FIGS.

(5.4) Configuration of Control System FIG. 14 shows an example of the configuration of the control system of this embodiment.

Here, reference numeral 800 denotes a controller constituting a main control unit, for example, a CPU 801 in the form of a microcomputer for executing the procedures shown in FIGS. 15 and 20, a ROM 803 storing programs corresponding to the procedures and other fixed data. ,
And a RAM 805 provided with an area for developing image data, a work area, and the like. Reference numeral 810 denotes a host device (which may be a reader unit or the like) serving as a supply source of image data. Image data and other commands and status signals are transmitted to and received from the controller via an interface (I / F) 812.

Reference numeral 820 denotes a power switch 822, and recording (copy)
A group of switches, such as a copy switch 824 for instructing start and a large recovery switch 826 for instructing activation of large recovery, receives a command input by an operator. Reference numeral 830 denotes a sensor 832 for detecting the position of the carriage 2 such as a home position and a start position, and a sensor 834 including a leaf switch 530 and used for detecting a pump position.
Etc. are a group of sensors for detecting the state of the device.

Reference numeral 840 denotes a recording head 86 according to recording data or the like.
Is a head driver for driving the discharge energy generating element (the electrothermal transducer in this example). Reference numeral 850 is a main scanning motor for moving the carriage 2 in the main scanning direction (the left-right direction in FIG. 7), and 852 is its driver. A sub-scanning motor 860 is used to convey (sub-scan) the recording medium, and in this example, drives the pressure roller 510 via the roller 15. 854 is its driver. 87
Numeral 0 denotes a suction pump such as the above-mentioned tube pump, and its driving is controlled by a motor driver 853.

(5.5) Control Procedure FIG. 15 is a schematic flowchart of a recording processing procedure according to this embodiment.

When the power switch 822 is operated and the power is turned on, this procedure starts, and first, an initial process (the process of FIG. 16) is performed in step SA. Next, in step S1, a print start command signal such as an operation of the copy switch 824, a command from the host device 810, or a so-called manual feed paper feed signal is awaited. When this is instructed in accordance with the input of image data from the host device 810, a recording preparation process (the process of FIG. 17) is performed in step S13.

Then, in step S3, a predetermined number of lines (5 to 10 in this example) are recorded, and in step S5, it is determined whether the recording of one page is completed. If a negative determination is made here, the recovery process at the time of recording in step SC (the process of FIG. 18) is performed, that is, one recovery process is performed each time the recording of a predetermined number of lines is completed. After performing the recording end processing (the processing in FIG. 19), step S1 is performed.
Move to

Next, the details of steps SA to SD and the details of the large recovery process will be described with reference to FIGS. 16 to 19 and FIG. The sequence in FIGS. 16 to 20 is shown in FIG.
13 (a) to 13 (e) respectively.

First, as shown in FIG. 16, at the time of initial processing, the home position (position (D)) of the carriage 2 is set in step SA1. At this time, the pressure roller 510 is set at the position (L) (hereinafter, this position is also referred to as the roller home position). In setting the carriage 2 to the home position, the movement is used to drive the cap holder 330 and the blade holder 510. Therefore, the carriage 2 is not overlapped with the recovery system unit to obtain an appropriate inertia force. (For example, the position (A) in FIG. 12 (a)), so that the approaching is performed. Then, by setting to the home position, the recording head 86 is capped, and the space inside the cap is closed. Further, at this time, the blade 401 is in the raised position since the blade 401 is projected and locked (the position is passed through the position (C) in FIG. 12), and the operation is the same in the following. If the carriage 2 and the roller 510 are already at the home position, this step may be skipped.

Next, step SA3 moves the carriage 2 to the position.
By moving toward (A), wiping of the discharge port forming surface is performed. This is because the blade 401 has already protruded due to the setting of the carriage 2 to the home position. The movement at this time is, as described above, a speed lower than that during normal printing scanning, that is, the blade 401 moves to a step.
Wiping is performed at a speed at which reliable wiping is performed.

Next, in Step SA5, the pressure roller 510 is rotated to the position (K), and in Step SA7, the carriage 2 is set to the start position (the position shown in FIG. 12 (B)). Discharge is performed. That is, idle discharge is performed after wiping. This is the same in the following processing,
In this example, idle discharge is always performed after wiping.
The carriage 2 is engaged with the release lever in accordance with the movement to the start position, and the blade 401 is lowered as described above to operate the release lever.

Here, the idle ejection is performed to prevent color mixing or the like which may be caused by wiping a plurality of recording heads with one blade. In this example, in order to perform this more effectively, As a print head wiped later or a print head corresponding to ink with a higher brightness (yellow or the like) is more prominent in color mixing, idle printing is carefully performed on such a print head. In other words, the print head in which the color mixture easily occurs has a longer time for performing the idle ejection process, or has a larger number of ejections.

In this example, the driving frequency of the electrothermal transducer is set lower during idle discharge than during normal printing (for example, 1 /
4). This is because it has been confirmed that when the driving frequency is low, the wetting of the ejection port forming surface with the ink is small. Further, when performing idle discharge, a predetermined number of discharge port groups (for example, 8
), And the electrothermal converter is driven sequentially for each block. It has been confirmed that this also makes it difficult to cause wetting. These aspects are the same in idle discharge performed below.

In order to make it difficult to cause wetting, the width, voltage, shape, etc. of the driving pulse may be changed instead of or together with changing the driving frequency. It can be determined.

After such idle discharge, step SA9 is performed.
To set the carriage 2 and the roller 510 to the home position. Here, capping is performed by first setting the carriage 2 to the home position. At this time, since the roller 510 is set to the position K and communication with the atmosphere is established in step SA5, the cap inner volume at the time of capping is set. Due to the change, no positive pressure acts on the inside of the cap, so that no air is mixed into the inside of the discharge port.
Thereafter, the roller 510 is rotated in the negative direction in FIG. 11 (the ink is absorbed by the positive rotation, which is not preferable from the viewpoint of reducing the consumption), and is set to the position (L). As a result, the inside of the tube 304 or the cap is slightly pressurized, and the ink received by the previous empty discharge remains without being sucked, and the inside of the cap is kept in a humid atmosphere. Evaporation of the solvent component is less likely to occur.

When recording start is instructed (step S1)
Before the recording operation (step S3), preparation processing is performed as shown in FIG. Here, first step SB1
Perform the same wiping as in step SA3 above (this procedure is performed after the home position is set in step SA9, so that the blade 401 is already at the raised position, and therefore the wiping is performed by moving to the position (A) of the carriage. Next, the carriage 2 is set to the start position and idle discharge is performed in the same manner as in step SA7, and the subsequent printing operation is always performed from this position (B).

In the recovery processing at the time of recording performed for every predetermined number of lines of recording, as shown in FIG. 18, first, at step SC1, the carriage 2 is moved to the position (C), and the blade holder 410 is driven. The blade 401 is protruded. Thereafter, similarly to the above steps SB1 and SB3, wiping (step SC3) and setting to the start position and idle discharge (step SC5) are executed. If this procedure is executed while the recording medium is conveyed, the recording throughput will not be significantly reduced.

After the recording of one page is completed and the recording medium is discharged, the pressing roller 510 is continuously moved to the position as shown in FIG.
(K) (step SD1). Then, in this state, the carriage 2 is set to the home position in step SD3, and capping is performed.

Next, a small recovery operation is performed in step SD5. Here, the pressure roller is first set to the position (M), and ink suction is performed while maintaining the position for a predetermined time (for example, 0.1 second). Thereafter, in steps SD7, SD9, SD11 and SD13, the same processing as in the above steps SA3, SA5, SA7 and SA9 is performed, and the apparatus holds the next recording start command with the recording head capped. Become.

When the large recovery switch 826 is operated, FIG.
Is started. In this procedure, after setting the home position (position (D)) of the carriage 2 and the home position (position (L)) of the pressure roller 510 in step SE1, the large recovery in step SE3 is performed. Do. Here, the pressure roller 510 is rotated in the positive direction and reset to the position (L), and ink suction is performed while maintaining the position for a predetermined time (for example, 2 to 3 seconds). At the same time, a predetermined idle discharge operation is performed. Then, in steps SE5, SE7, SE9 and SE11, steps SA3, SA5, SA7 and SA9 in FIG.
Is performed, and the procedure ends. In order to simultaneously perform the suction and the idle discharge, for example, predetermined idle discharge drive data may be set in the driver 840 prior to the large recovery, and the drive may be started at an appropriate timing.

The purpose and effect of performing idle discharge together with ink suction during the large recovery process as in this example are as follows.

FIG. 21 shows a state in which dissolved gas is deposited in the ink inside the head chip due to standing or the like, and residual bubbles and the like at the time of ejection are gathered and many bubbles are present.

In this state, when an ejection energy generating element such as the electrothermal conversion element 112 is driven to perform an ejection operation for recording, ink is supplied from the liquid chamber 106 to the ejected liquid path 107. Therefore, the ink flows in the common liquid chamber 106. As a result, a negative pressure is generated, so that air bubbles are collected in the liquid path, which hinders the supply of ink to the liquid path. Therefore, the ejection becomes unstable, and the ejection or non-ejection occurs. In severe cases, air bubbles may adhere to the rear end of the liquid path and completely cut off the supply of ink into the liquid path, resulting in non-discharge.

When a large number of air bubbles are present, the ejection becomes unstable. Therefore, the air bubbles are usually removed from the air bubbles by suction, pressure or the like. However, when a high-viscosity ink is used or when the ink has a high viscosity in a low-temperature environment, even if the ink is recovered by suction or the like, almost no bubbles can be removed. On the contrary, they just waste ink.

FIG. 22 shows the size of bubbles and the rate of remaining bubbles that could not be removed even by suction.

At this time, the liquid path diameter of the recording head was 40 μm, and a multi-nozzle head having 64 discharge ports was used. The maximum negative pressure generated by the suction pump is -0.5 atm.

It can be seen from this figure that it is difficult to remove bubbles larger than the liquid path diameter, but it is easy to remove bubbles above a certain size. In other words, bubbles smaller than the liquid path diameter can of course be removed, but even bubbles larger than the liquid path diameter become deformed and enter the liquid path if they become larger than a certain size, and the bubbles communicate with the outside air through the liquid path. It is considered that the ink fills the liquid path again.

As shown in the figure, by increasing the negative pressure of the pump (−0.5 atm → −0.6 atm), the remaining rate of air bubbles can be reduced. It is not desirable from the point of view of development.

Further, the above is particularly remarkable when the dye concentration of the ink is increased in order to realize high density, or when the size of the ejection port is reduced in order to achieve high resolution. High dye concentration means high viscosity, so if you remove bubbles of the same size for a large discharge port with a small discharge port, you must significantly deform the bubbles and make them smaller than the discharge port. No.

When suction is performed, it is difficult to remove air bubbles unless a pump that generates a considerable negative pressure is used. In some cases, ink is discharged only from a liquid passage that is not blocked by air bubbles during suction. Since the flow of ink in that portion becomes faster and the flow of ink in the liquid passage portion blocked by air bubbles becomes slower, the negative pressure becomes relatively higher when the ink flow is faster, so that the air bubbles are further reduced. It is difficult to remove.

Therefore, in this example, the ink is ejected simultaneously with the suction at the time of the large recovery in step SE3.

That is, since the ink in the liquid path is discharged, the negative pressure in the liquid path after the discharge is instantaneously increased, and in combination with the suction negative pressure, the pressure is considerably stronger than that of the pump alone. Since a negative pressure is generated, and the negative pressure acts equally on each of the liquid passages, it is easy to remove bubbles. Further, in the case of this example, since the electrothermal transducer 112 as a means (ejection energy generating element) for generating bubbles at the time of ejection is driven, the temperature of the ink in each liquid passage increases, and the viscosity decreases. In addition, since the surface tension is reduced, the resistance of the flow path in the liquid path is further reduced, and the removal of air bubbles is further facilitated. In particular, when the head is left for a long time, the thickening is considerably advanced, which is effective.

In other words, as shown in FIG. 23 (a), when the cap is brought into close contact with the entire surface on which the ejection port is formed, and the ink is ejected from the ejection port at the same time as the suction is performed by the pump. Bubbles that were only drawn to the end but were not sucked out are drawn to the rear end because the simultaneous discharge causes ink flow in the liquid path and increases the negative pressure in the liquid path. The air bubbles enter the liquid path and are discharged outside.

As a result, as shown by the one-dot chain line in FIG. 22, bubbles inside the discharge port are removed, and stable discharge can be performed.

(6) Other Embodiments In the second embodiment of the present invention, when performing discharge simultaneously with suction, drive conditions are set to be equal to or higher than the ink refill frequency which is the limit of the discharge characteristics of the head. Then, the bubbles in the liquid path are pulled backward by the suction, and the bubbles enter the liquid path due to an increase in the negative pressure in the liquid path due to the discharge. On the other hand, the meniscus is vibrating at the liquid path front end because the ejection is performed at a frequency higher than the limit of the refill frequency. When the frequency, in other words, the foaming interval is the time at which the retraction of the meniscus is the maximum, the foamed bubble from the electrothermal transducer (discharge heater) and the meniscus are united, and the rear end of the meniscus becomes sharp.

Thus, the bubbles in the liquid chamber entering from the rear end of the liquid path and the rear end portion of the meniscus increased from the front end are united.

When this state occurs over the entire head, air flows into the liquid path from outside at once,
Insufficient ink inside the liquid chamber ("ink drop")
). Since the ink runs out, the bubbles are absorbed and disappear.

In the cartridge C of this embodiment, if the ink tank 80 is filled with an absorber or the like and the head is set at a negative pressure with respect to the atmosphere, the above-described ink drop is promoted. However, in such a cartridge, even if ink drops occur, only the ink inside the ejection port of the head chip runs out, and most of the ink returns to the tank. Therefore, the ink hardly comes out of the head, and the ink is not wasted.

Then, as shown in FIG. 23 (b), after the ink inside the ejection port is almost exhausted, suction is performed next. At this time, the suction capacity of the pump is set so that the inside of the head chip is filled with ink and an extra amount of suction can be performed.

As a result, the amount of waste ink required for recovery can be reduced as much as possible, and the running cost of the cartridge and hence the printing apparatus can be reduced.

In the third embodiment of the present invention, before the processing according to the first or second embodiment is performed, an external heater is driven or heat is generated so that the discharge heater does not discharge. The ink temperature in the liquid path is increased by driving or the like, so that the viscosity and surface tension of the ink are reduced. This makes it easier for the bubbles to coalesce into large bubbles, and also increases the fluidity of the ink.
As shown by the solid line in FIG. 20, the effect of the first or second embodiment is further improved. In the case of applying the method of dropping ink as in the second embodiment, the meniscus force at the leading end of the liquid path is weakened because the surface tension of the ink is reduced. Therefore, it is possible to effectively cause ink dropping without making the ejection interval shorter than the shortest ejection interval of the main body (corresponding to the so-called solid printing).

In the fourth embodiment of the present invention, the liquid paths to be driven at the time of suction are limited to specific ones (for example, the liquid paths at both ends of a plurality of liquid paths are driven and the central area is not driven). That is, when the liquid is discharged from all the liquid paths, the bubbles may be hardly deformed because one bubble receives the force from a plurality of liquid paths, whereas the negative pressure is concentrated from a predetermined part of the liquid paths. , The degree of deformation of the bubbles can be increased.

In the fifth embodiment of the present invention, as shown in FIG. 23 (c), the start timings of the suction and the discharge are not completely simultaneous but slightly shifted. That is, the maximum generated pressure at the time of suction and the maximum negative pressure of discharge or the like are made to be the same. The maximum negative pressure at the time of discharge is when the foamed foam disappears and is almost the same as the discharge, but the maximum pressure generated by the pump is delayed by the time required for the rollers of the pump to move. That is, it is better to perform the suction operation somewhat earlier than the discharge operation. As a result, the removal rate of bubbles can be dramatically increased.

The present invention is not limited to the embodiments described below, and it is needless to say that any desired modifications can be made without departing from the spirit of the present invention. Such modifications, in addition to those described elsewhere, include, for example, the following.

For example, in the case of the small recovery process, if necessary, the suction may be performed at the same time as the suction, or the large recovery process may be appropriately divided into two types. May be provided.

Further, the pump for applying the suction force is not limited to the one using the tube and the roller as in the above example, but may be the one comprising a cylinder and a piston. Further, not only a device that sucks ink from the ejection port to perform forced discharge but also a device that pressurizes the ink supply system may be used.

FIG. 24 illustrates a flowchart of another preferred embodiment of the present invention as a recovery mode, without being limited to each preferred type of the above-described apparatus configuration.

The state of recovery according to the present invention is so preferable that a uniform and large amount of ink can be discharged from each discharge port of the head per unit time.

In this example, the recovery mode step ST1 is adopted as a flowchart, by a signal from a selection key, or as a normal main suction recovery.

A heating process step ST2 for the ink in the head is performed according to the recovery mode command. In this step ST2, it is preferable to raise the temperature inside the common liquid chamber, but it may be only inside the liquid path of the head. Preferably, both of these are good. Well-known means such as an external heater and a liquid chamber heater can be used as the common liquid chamber heating. Liquid path heating can be obtained only by supplying an electric signal so as to perform the above-described preheating if the discharge energy generating element is a heating element that forms bubbles. Conversely, electricity
When a mechanical converter is used as an element, heating may be performed by using a heater capable of heating each liquid path or the whole, light energy, or the like. This step ST2 has the advantage that the inertial force due to the fluid resistance between the ink and the inner wall of the head is reduced, and the load during the initial movement of the ink can be reduced.

Next, the ink discharging element driving step ST3 drives the suction means (and / or the pressure means) in the step ST3.
4 and almost simultaneously. This has the effect of immediately starting or speeding up the movement of the ink itself with the start of ink suction by the suction means. As described above, it is possible to achieve uniform ink suction acting force to each of the plurality of liquid paths and the discharge ports at the time of ink suction and also to improve the recovery efficiency.
In the present invention, the steps ST3 and ST4 are performed substantially simultaneously.
The conventional suction recovery does not involve an increase in the size of the recovery pump device, and includes all the components that can obtain a uniform suction operation over the whole in a relatively short time and an excellent recovery effect as a whole. In order to simultaneously perform steps ST3 and ST4, a plurality of processors may be provided.
On the other hand, with respect to (for example, element driving), if a means for setting the driving data is provided and the driving is performed by the means in response to a command, the processing can be performed by a single processor.

In each of the above embodiments, the problem of the prior art can be solved because the inertia of the ink is reduced to improve the initial ink discharge state.

Next, referring to FIG. 25 and FIG. 26, the present invention has a recovery combined period in which the drive period of the discharge energy generating element and the forced discharge period using a suction or pressurizing pump are used together. Another example of the recovery mode according to the present invention will be described. The following description includes a plurality of inventions that attempt to solve substantially the same problem.

In FIG. 25, the time T is plotted on the horizontal axis, and the time T is used in common. The pressure P (static pressure) on the vertical axis indicates the pressure change during the forced discharge period, and the pulse on the vertical axis during the element driving period. 3 shows the voltage V. PMAX is generated at time T ₄ at a maximum pressure during the forced discharge period. This can be mentioned, for example, when the maximum pressure is generated during one stroke of the pump. In this example, P2 indicates a pressure value of 50% of the maximum pressure PMAX, and P1 indicates a pressure value of 30% of the maximum pressure PMAX. The time indicating these pressures P1 and P2 is T2, T
3 The pressures P1 and P2 are generated during the pressure increase and during the pressure decrease, and the time when the pressure P1 is generated is time T5. Time T1 is when pressure is generated, and time T6 is when pressure disappears. T0 is the time when the recovery mode start signal is received.

In this example, a plurality of pulses PUL of the recovery voltage VP are input between time T3 and time T4. Each of the plurality of pulses PUL is inputted substantially simultaneously to all the ejection energy elements of the recording head. In this example, at least one element drive pulse is supplied during a forced ink discharge period from 50% of the maximum pressure PMAX at the static pressure to the maximum pressure PMAX. Therefore, according to this example, since the recovery force in the first half during the pressure rise is sharply increased sharply from the middle, it is possible to prevent the loss of the increase in the pressure that the initial recovery force is offset by eliminating the inertia force of the ink. it can. For this purpose, time
It is a preferable condition that the element drive pulse is given at T2 or more, that is, 30% or more of PMAX. Needless to say, the increased pressure is preferably caused by the formation of bubbles by the heating element, because it is sharper than that of the piezoelectric element.

A further example will be described with reference to FIG. In the above example, the element driving pulse PUL is input while the pressure P is increasing, but the increase in the restoring force, that is, the increase in the total pressure, can be achieved by adding the element driving pulse while the pressure P is decreasing. From this point of view, it is preferable to add the pulse until the time T5 when the pressure P1 is reached, preferably during the existence period of the pressure P until the time T6. Next, when considering the end of the forced discharge period and the end of the element driving period,
Since the pressure P of the forcible discharge is decreasing, it is conceivable that a small amount of the ink slightly comes out of the vicinity of the ejection port due to the minute pressure and remains on the ejection port surface, and a predetermined period after T6 when the pressure P disappears, that is, the time It is preferable to continue supplying the element drive pulse PUL until T7 to further improve the state of each ink path with a rapid discharge force.

By the way, in the flowchart of FIG. 20 described above, after executing the recovery mode having the large recovery, that is, the combined recovery period, the discharge port surface is cleaned, and then the sequence of performing the idle discharge is as follows. It is preferred. That is, the large recovery is used for both the purpose of removing the air bubble accumulation in the head and the purpose of discharging the cause of the clogging to the outside of the discharge port. At this time, undesired substances such as dust and solids that have come out of the discharge port may remain around the discharge port. The cleaning step is important for effectively removing this. Even if there is a minute undesired substance that is slightly returned to the discharge port side by this cleaning, it can be surely removed by the discharge force of the empty discharge and even from the discharge port surface without being removed by a large recovery. It is.

Further, consideration will be given to the start of the forced discharge period and the start of the element driving period. At the beginning of the recovery process, there is an inertial force due to the close contact state between the ink and the ink path wall or the ink chamber wall. If the recovery pressure depends on the pumping force for forcible discharge, energy loss is large. As an example of solving this, the start of the element driving period is applied at the time T1 when the pressure P is generated. According to this,
It is preferable because the pump power is effectively used. Further time T1
It is more preferable that the element is driven during the period from to T2. In addition, it is preferable to start the element driving period before the time T1 and before the recovery signal is output T0 because the ink flow state of all the ejection ports can be formed before the forcible ejection. It is preferable that the element drive pulse supplied from the start of the preceding element drive period to the above-described combined recovery period has a constant cycle. Further, in order to obtain the maximum recovery force, it is a preferred embodiment that the element driving pulse is applied at the time T4, specifically, the maximum growth time of the bubble formed by the heating element is matched.

It goes without saying that the description of each component relating to FIG. 25 described above in the present invention includes all components obtained by arbitrarily combining the components.

Next, a special embodiment of the present invention will be described with reference to FIG. The present embodiment is a special one of the embodiments in which the normal recovery mode and the above-mentioned recovery combined mode are provided as the recovery modes, and these are switched and executed. That is, when an absorber is provided in the ink storage unit, the range of the negative pressure fluctuation usually becomes −30 mmHg to −120 mmHg in many cases. In this case, when the negative pressure is small, for example, with a negative pressure smaller than -50 mmHg, if sufficient recovery can be obtained only by normal recovery, the above-mentioned large recovery may be performed only in the negative pressure range of -50 mmHg to -120 mmHg. Become. When the amount of ink used exceeds a predetermined value, a large recovery may be required.

In such a case, it is a preferable embodiment to perform switching as described below, since performing a large recovery at all times results in ink loss. In the flowchart of FIG. 26, as described above, when the reference value is determined by a detection mechanism such as an integrated count or residual detection (SM1), if the reference value is larger than the reference value (in the case of a negative pressure, the absolute value is taken). 3) shows a subroutine for performing normal recovery SM3 such as only idle discharge or only suction, and selecting the combined recovery mode SM2 above the reference value. The reference value may be, for example, | -50 mmHg | described above, but is not limited thereto. In any case, a method in which the recovery combination mode is selected as necessary is included in the present invention. Further, the present invention includes the above-described various embodiments as a plurality of execution processes in the combined recovery mode, and arbitrarily selecting and using these processes. Above all, the above-described second embodiment is preferable and maximizes the resilience.

The present invention can exert a tremendous effect on a tube pump which becomes large to generate a large pressure, a recovery mechanism for a plurality of color heads, and the like.

(7) Others The present invention brings about an excellent effect particularly in a bubble jet type recording head and recording apparatus proposed by Canon Inc. among ink jet recording methods. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

As for the representative configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to a sheet or a liquid path holding a liquid (ink). Electrothermal transducers
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, thereby causing film boiling on the heat acting surface of the recording head. As a result, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed, which is effective. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. If this drive signal is pulse-shaped, the growth and shrinkage of the bubble are performed immediately and appropriately,
In particular, liquid (ink) discharge with excellent responsiveness can be achieved,
More preferred. As the pulse-shaped drive signal, those described in U.S. Pat. Nos. 4,463,359 and 4,434,262 are suitable. If the conditions described in the specification of US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, The present invention also includes a configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600 which disclose a configuration in which a heat acting portion is arranged in a bending region. In addition, Japanese Patent Application Laid-Open No. S59-5959 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters.
The effect of the present invention is also effective in a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy is made to correspond to a discharge portion.
That is, recording can be performed reliably and efficiently regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, when the recording head is fixed to the apparatus main body or is attached to the apparatus main body, the recording head is electrically connected to the apparatus main body and ink from the apparatus main body is discharged. The present invention is also effective when a replaceable chip-type recording head that can be supplied is used.

The type and number of recording heads to be mounted are, for example, not only those provided for one color ink but also a plurality of inks having different recording colors and densities. A plurality may be provided.

In addition, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

As described above, according to the present invention, the timing drive is performed so that the forcible discharge operation by suction or pressurization and the discharge operation by driving the discharge energy generating element are performed substantially at the same time. Bubbles can be easily removed. Further, since it is not necessary to increase the capacity of the forced recovery means such as a pump for performing suction or pressurization, it is possible to reduce the size and cost of the recording apparatus main body.

[0162]

As described above, according to the present invention,
By simultaneously performing the forcible discharge operation by suction or pressurization and the discharge operation by driving the discharge energy generating element, it is possible to easily remove bubbles inside the discharge port. Further, since it is not necessary to increase the capacity of means such as a pump for performing suction or pressurization, it is possible to reduce the size and cost of the recording apparatus main body.

In addition, the recovery ability of the given forced recovery means can be efficiently improved, and a reliable recovery can be achieved without increasing the size of the apparatus.

Further, since the small recovery step is included in addition to the large recovery step, the ink is more slowly sucked from the discharge port in the small recovery step than in the large recovery step, and the flow of the ink is stabilized. Will be done. Therefore,
If the suction force is large and the ink flow is not stable, turbulence and fine bubbles that are not removed by eddies can be reliably removed. In the small recovery step, the amount of ink to be sucked is also reduced, so that unnecessary consumption of ink can be avoided. That is, there is little wasted waste ink,
Moreover, there is an advantage that an optimum and quick recovery can be performed.

In addition, the degree of recovery is superior to that of the prior art, and the processing time can be shortened, and the amount of ink loss can be optimally reduced.

In addition, efficient suction can be obtained from the start of the recovery process without increasing the size of a mechanism such as a tube pump.

[Brief description of the drawings]

FIG. 1 is a perspective view of a recording head / ink tank integrated type cartridge used in an embodiment of the present invention.

FIGS. 2A and 2B are a front view and a side sectional view, respectively, showing a configuration example of the recording head.

FIG. 3 is a plan view showing the vicinity of a carriage of the apparatus in which the cartridge shown in FIG. 1 is mounted.

FIG. 4 is a side sectional view for explaining a recording apparatus configured by using the apparatus of the embodiment.

FIG. 5 is a schematic perspective view of the apparatus according to the present embodiment, showing the outline of a recovery system unit that is a main part of the apparatus.

FIG. 6 is a plan view showing a detailed configuration example of the recovery system unit.

FIG. 7 is a side view of the same.

FIG. 8 is a front view for explaining a detailed configuration and operation of a cap unit provided in the recovery system unit.

FIG. 9 is an explanatory diagram for explaining an aspect of wiping by a blade that is raised and lowered by a blade lifting mechanism.

FIGS. 10A and 10B are explanatory views for explaining a mode of cleaning the blade.

FIG. 11 is an explanatory diagram for explaining the operation of the ink suction mechanism employed in this embodiment.

FIGS. 12A to 12D are explanatory diagrams for explaining a carriage position at the time of recovery processing in the embodiment.

FIGS. 13A to 13E are explanatory diagrams for explaining the relationship between the ink suction mechanism shown in FIG. 11 and the operating position of the carriage shown in FIG. 12 when the sequence of this embodiment is executed. is there.

FIG. 14 is a block diagram illustrating a configuration example of a control system according to the present embodiment.

FIG. 15 is a flowchart illustrating an example of a schematic recording operation procedure by the control system illustrated in FIG. 14;

FIG. 16 is a flowchart illustrating an example of an initial processing unit by a control system.

FIG. 17 is a flowchart illustrating an example of a recording preparation processing unit.

FIG. 18 is a flowchart illustrating an example of a recording recovery processing unit.

FIG. 19 is a flowchart illustrating an example of a recording end processing unit.

FIG. 20 is a flowchart showing an example of the same large recovery processing procedure.

FIG. 21 is an explanatory diagram for explaining a state of bubbles existing in a head chip.

FIG. 22 is an explanatory diagram for explaining effects of the embodiment of the present invention.

FIGS. 23 (a), (b) and (c) are timing charts showing driving states during a large recovery process in each embodiment of the present invention.

FIG. 24 is a flowchart showing another preferred embodiment of the present invention.

FIG. 25 is an explanatory view for explaining still another preferred embodiment of the present invention.

FIG. 26 is a flowchart showing another embodiment of the present invention.

[Explanation of symbols]

 C cartridge 2 Carriage 80 Ink tank unit 86 Recording head 103 Orifice plate 108 Discharge port 109 Pressing member 300 Cap unit 302 Cap 303 Holder 304,305 Tube 330 Cap holder 332,334 Pin 342 Engagement unit 350 Recovery base 401,402 Blade 403 Blade cleaner 410 Blade holder 430 Lock lever 440 Release lever 450 Cam member 500 Pump unit 502 Regulatory surface 504 Pump shaft 510 Pressure roller 520 Guide roller 528 Pump drive gear 530 Leaf switch 532 Cam 800 Controller 810 Host device 820 Switch group 830 Sensor group 850 Main scanning motor 860 Sub scanning motor

(72) Inventor Miyuki Matsubara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Atsushi Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) reference Patent Sho 63-295268 (JP, a) JP Akira 63-295267 (JP, a) JP flat 1-285355 (JP, a) (58 ) investigated the field (Int.Cl. ⁷ B41J 2/18 B41J 2/05 B41J 2/175 B41J 2/185

Claims (14)

(57) [Claims] A recording head having an energy generating element for generating energy used for discharging ink from a discharge port; a cap for covering the discharge port of the recording head; And a suction unit for performing suction from the discharge port when covering the discharge port. In the recovery processing method of the ink jet recording apparatus, the discharge port from the discharge port by the suction unit in a state where the discharge port is covered with the cap. A large recovery step of performing suction and discharging the ink from the discharge port by driving the energy generating element; and suctioning from the discharge port by the suction unit with the discharge port covered with the cap. A small recovery step of performing only suction to apply a suction force smaller than the suction force in the large recovery step and discharging ink from the discharge ports. , Recovery processing method for an ink jet recording apparatus which comprises a. 2. The method according to claim 1, wherein the energy generating element is a heating element, and in the large recovery step, a drive signal for forming a bubble in the ink is supplied to the heating element.
4. The recovery processing method for an ink jet recording apparatus according to item 1. 3. The method according to claim 2, wherein in the large recovery step, a plurality of the drive signals are supplied to the heating element to perform the ink discharge a plurality of times. 4. The method according to claim 1, wherein the large recovery step is performed after the apparatus has been stopped for a long period of time. 5. The method according to claim 1, wherein the large recovery step is performed when the ink ejection state does not become good even after performing the recovery processing on the print head. . 6. The method according to claim 1, wherein the small recovery step is performed immediately after a predetermined amount of printing operation. 7. A print head having an energy generating element for generating energy used for discharging ink from a discharge port, a cap for covering the discharge port of the print head, and the cap being provided with the discharge port. And a suction unit for performing suction from the discharge port when the ink is covered. A heating step of heating the ink in the recording head, and the cap after the heating step. A large recovery step of performing suction from the discharge port by the suction unit in a state where the discharge port is covered, and driving the energy generating element to discharge ink from the discharge port, after the heating step, Suction from the discharge port by the suction means with the cap covering the discharge port, which is smaller than the suction force in the large recovery step. Recovery processing method for an ink jet recording apparatus which comprises a small recovery step, the which performs only suction exerting a suction force ejects ink from the discharge port. 8. The heating element according to claim 7, wherein the energy generating element is a heating element, and in the large recovery step, a driving signal for forming a bubble in the ink is supplied to the heating element.
4. The recovery processing method for an ink jet recording apparatus according to item 1. 9. The method according to claim 8, wherein in the large recovery step, a plurality of the drive signals are supplied to the heating element to perform the ink discharge a plurality of times. 10. An ink jet recording apparatus which performs recording with a recording head having an energy generating element for generating energy used for discharging ink from a discharge port, comprising: a cap for covering the discharge port of the recording head; A suction means for performing suction from the discharge port when the cap covers the discharge port; and causing the suction means to perform suction from the discharge port with the discharge port covered by the cap. At the same time, a large recovery process in which the energy generating element is driven to perform ink discharge from the discharge port, or the suction unit in the state where the discharge port is covered with the cap has a suction force in the large recovery process. A control unit that performs a small recovery process of performing only suction to apply a small suction force and performing ink discharge from the discharge port. An ink jet recording apparatus, comprising: 11. The ink jet recording apparatus according to claim 10, wherein the large recovery processing is performed after the apparatus has been stopped for a long period of time. 12. The ink jet recording apparatus according to claim 10, wherein the large recovery process is performed when the ink ejection state does not become good even after performing the recovery process on the print head. 13. The ink jet recording apparatus according to claim 10, wherein the small recovery processing is performed immediately after a predetermined amount of recording operation. 14. The ink jet recording apparatus according to claim 10, wherein the control unit drives the energy generating element so that the ink is heated prior to the large recovery processing and the small recovery processing.