JP2810522B2 - Recovery method for liquid discharge recording device - Google Patents

Description

The present invention relates to a copying machine, a facsimile, a computer, a word processor, or a combination thereof, which includes a suction recovery device that sucks a liquid and then discharges the liquid from inside a pump. More specifically, the present invention relates to a recovery method for a liquid ejection recording apparatus in which the suction recovery device is applied to an ink receiving member such as a cap for receiving ink discharged from a recording head. Things.

2. Description of the Related Art Conventionally, in a recording apparatus of an ink jet system that performs recording on a recording medium (hereinafter, referred to as “recording paper” or simply “paper”) such as cloth, paper, and an OHP sheet,
In general, a print head with an array of fine discharge ports is used, so ink is not suitable for discharge or printing when bubbles or dust are mixed into the discharge ports or due to viscosity increase due to evaporation of the ink solvent. A process for removing the cause of the discharge failure (discharge recovery process) is performed before or in the absence state.

Normally, a preliminary ejection (often directed to a cap, an ink absorbing sheet, or a sponge) for performing ejection different from recording or a suction-recovery pump which communicates with a cap and applies a suction force is known.

On the other hand, an appropriate portion of the apparatus is provided with a waste ink tank for storing waste ink generated by the above-described ejection recovery process. The pump is opened with the cap open to the atmosphere in order to perform a process of guiding the ink received by the ejection recovery device including the cap and the pump and the waste ink tube and the like that communicate with these to the waste ink tank by the ejection recovery process. Is operated to suck ink together with air, that is, an operation called so-called empty suction. This is an extremely effective operation to prevent solidification of the residual waste ink or leakage of the waste ink from the cap to the outside when the ink received in the discharge recovery device by the discharge recovery process is left unattended. It is.

In addition, this type of pump is used in various fields as a means for sucking not only ink but also ordinary liquid and discharging it to a specific portion.

[Problems to be Solved by the Invention] However, the above-mentioned idle suction is usually performed at a high speed in order to cause a delay in the processing step, and it has been found that the sucked liquid is caused to flow backward. This tendency was observed with prolonged use of the pump.

On the other hand, the internal structure of the suction recovery mechanism has been simplified,
In the case where suction is performed without providing a normal backflow prevention valve mechanism, the above-described problem of the backflow is often observed.

In addition, since the suction recovery mechanism occupies a large volume inside the apparatus, it has been required that the apparatus itself be downsized in order to achieve downsizing of the apparatus. However,
The more the miniaturization is promoted, the greater the problem of the backflow becomes, and it has been confirmed at the stage of achievement of the present invention that the solution of the problem is important.

 The present invention solves the above-mentioned problems.

Means for Solving the Problems According to the present invention, as a configuration for preventing the backflow, a cap for contacting a recording head provided with a discharge port for discharging liquid and covering the discharge port is provided. A suction pump having a cylinder communicating with the cap and a piston reciprocating in the cylinder, and suctioning from the discharge port by moving the piston in a state where the inside of the cap is not in communication with the atmosphere. A recovery method for the liquid discharge recording apparatus, wherein the piston is moved from the top dead center side to the bottom dead center a plurality of times in a state where the inside of the cap is in communication with the atmosphere, whereby waste liquid is discharged from the suction pump. Providing a recovery method for a liquid discharge recording apparatus, wherein the piston is stopped for a predetermined period at an inverted position on the bottom dead center side of the piston when performing idle suction for discharging the liquid. Is shall.

According to the present invention, the sucked liquid and the liquid being sucked can be reliably guided to the discharge direction by the stop period on the bottom dead center side after the liquid is sucked. Liquid can be reduced. In addition, in the recording apparatus employing the suction recovery apparatus of the present invention, which can achieve the miniaturization of the suction recovery apparatus itself and prevent the function thereof from being deteriorated, the volume of the recovery portion of the recording apparatus itself can be greatly reduced, so that the overall size can be reduced. It was possible to increase the reliability of recording by the recording head while achieving this.

Further, what is particularly noteworthy in the claims is as follows.

In particular, without a valve mechanism for preventing backflow, a liquid suction port is provided in the moving range of the piston, the piston is provided with an elastic sliding portion, and a discharge path for discharging the liquid is provided. The present invention is particularly effective for a pump having a gap with respect to the elastic piston shaft, since solving the problem of backflow affects the use of the pump.

The empty suction start position of the empty suction is not set to the top dead center for suction of the pump, but for the piston movement to the bottom dead center side, between the top dead center and the suction port, preferably By making the suction port side, more preferably near the suction port,
Since the amount of movement of the piston to the idle suction start position is reduced to restrict the range of movement of the piston that causes backflow of the liquid, it can greatly contribute to the prevention of the backflow.

Furthermore, by performing the idle suction a plurality of times, and inverting at the idle suction start position immediately without a stop period, even if a reverse flow phenomenon occurs to some extent, the reverse flow does not hinder the reverse flow. And the recovery processing time can be shortened. Therefore, in particular, the apparatus having this configuration can minimize the backflow phenomenon, and can realize efficient empty suction.

In the idle suction mode, after performing idle suction from the idle suction start position to the reversal position near the suction port,
By performing idle suction with the bottom dead center from the idle suction start position to the inversion position where the stop period is performed, the residual liquid in the pump can be significantly reduced, and the inconvenience due to the drying of the residual liquid and the state in the suction path are improved. The subsequent suction recovery operation can be performed well.

According to the present invention, there is provided an industrial advantage that enables the use of a pump having a small volume from the top dead center to the bottom dead center of the pump, particularly a pump of 1 cc or less, more preferably 0.1 cc or less. Can be

The present invention can stabilize the recording characteristics of a recording head using an electrothermal transducer, preferably utilizing film boiling, for a long period of time, and can synergistically enhance the use of this recording head. Thus, a stable recording apparatus can be provided.

As a configuration that further enhances the advantages of the present invention, the conventional top dead center is eliminated, and the empty suction start position itself is set as the top dead center of the pump, that is, immediately when the piston moves to the bottom dead center side. By satisfying the relationship that at least a part of the suction port sealing portion of the piston faces the ink suction port, the cause of the backflow can be greatly reduced. In this case, the reduction of the residual liquid can be further reduced.
In addition, in the case of this configuration, by setting the empty suction start position to a state where at least a part of the suction port sealing portion of the piston faces the suction port, the backflow problem can be more reliably solved.

In the following embodiment, as a countermeasure against the occurrence of a reverse flow caused by an impact or the like applied to the recording head during the idle suction, the recording head is not connected to the cap mechanism during the idle suction mode. It is also a preferable invention to provide a means for holding the device in an opposed state. Hereinafter, embodiments of the present invention will be described as including all of the above-described configurations. However, the present invention is not limited to the embodiments, and includes some or modifications thereof.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a flowchart which discloses a typical embodiment of the suction recovery device of the present invention.

The suction pump used in this embodiment will be described in detail with reference to FIG. 6, but the volume of piston movement from top dead center to bottom dead center is 178.2 mm ³ , The change was 144.25 mm ³ , the suction by hollow suction was 86.5 mm ³ by volume change, and 16.9 mm ³ by small empty suction following the suction step described later.
The pump employs a small pump mechanism without a special valve mechanism. Thereby, the occupied volume in the recording apparatus can be greatly reduced. Incidentally, the volume of the ink storage volume from the cap to the suction port of the pump in this embodiment is 3
6.68mm ^3. Compared to this ink storage volume,
Sky suction is about 4 times, hollow suction is about 2.4 times, and hollow suction about 3 times is about 7 times. The present invention is not limited to these numerical values.

In FIG. 1, since the cap in the closed state of the recording head is brought into communication with the atmosphere for idle suction, the head is separated from the cap or the valve of the cap is opened (step). Subsequently, after the elastic body for blocking the suction port of the piston is positioned at the empty suction preparation position near the suction port of the pump (step), the elastic body is positioned through the suction port to the hollow suction position (step). At the same time, a stop period (step) of 0.3 seconds is executed at this position.

This ensures a stable state in which the ink sucked into the pump can be discharged from the pump. Therefore, the cause of the reverse flow of the ink, which tends to occur during the conventional idle suction, is greatly reduced.

In the present embodiment, open air suction that can achieve a larger discharge than hollow suction is performed as compared with the hollow suction process.
At this time, the start position is the same as the above-mentioned idle suction preparation position, and the piston is returned to this position (step). After this,
After passing through the suction port, this elastic body is positioned (step) up to the sky suction position (bottom dead center).
Perform a 0.3 second pause period (step). As a result, the ink sucked into the pump, including the ink in the path from the cap to the pump, can be discharged from the pump, greatly reducing the amount of ink remaining in the pump and improving the inconvenience caused by the remaining ink. Yes, and secure a stable state. Therefore, it is possible to stabilize the recovery device capable of improving the recording of the recording head for a long period of time.

Note that the angle in FIG. 1 indicates a rotation angle of a cam described later, and does not limit the present invention.

The above-mentioned stop period is preferably 1 second or less, and among the practical cases described above, the sky suction is preferably 0.5 second or less.
Further, the lower limit is preferably 0.1 second or more.

FIG. 2 shows an example of an external configuration of a document creation device (hereinafter referred to as a "word processor") as a device to which the present invention can be applied.

Here, 1 is a keyboard unit which is an input device. Reference numeral 2 denotes a display unit that displays an input document or the like, is rotatably held, and is folded so as to overlap the keyboard unit 1 when not in use. Reference numeral 3 denotes an openable and closable protective cover provided at a viewing opening for checking the operation state of the recording head, and is transparent or translucent. Reference numeral 4 denotes a spur cover for holding the spur. Reference numeral 5 denotes a paper supporter that supports the paper when feeding and discharging the recording paper, and 6 denotes a knob for manually feeding and discharging the recording paper.

FIG. 3 shows a configuration example of a printer unit of the ink jet recording apparatus according to the present invention.

Here, reference numeral 9 denotes a head cartridge having an ink jet recording head, and 11 denotes a carriage for mounting the head cartridge and scanning in the S direction in the drawing. 13 is the head cartridge 9
Hook for attaching to the carriage 11, 15 is a hook
It is a lever for operating 13. This lever 15 has
A marker 17 is provided for indicating a scale provided on a cover, which will be described later, so that a print position and a set position of the head cartridge 9 by the recording head can be read. Reference numeral 19 denotes a support plate that supports an electrical connection to the head cartridge 9. Reference numeral 21 denotes a flexible cable for connecting the electrical connection unit and the main body control unit. twenty three
Is a guide shaft for guiding the carriage 11 in the S direction, and is inserted into a bearing 25 of the carriage 11. Reference numeral 27 denotes a timing belt for fixing the carriage 11 and transmitting power for moving the carriage 11 in the S direction, and is stretched over pulleys 29A and 29B arranged on both sides of the apparatus.

A driving force is transmitted to one pulley 29B from the carriage motor 31 via a transmission mechanism such as a gear. Reference numeral 33 denotes a platen roller for regulating the recording surface of a recording medium such as paper (hereinafter, also referred to as “recording paper”) and transporting the recording medium during recording or the like. 37 is a paper pan for guiding the recording medium to the recording position from the paper supporter 5 side, and 39 is disposed in the middle of the recording medium feeding path, presses the recording medium toward the platen roller 33, and conveys it. Feed roller for Reference numeral 41 denotes a discharge roller disposed downstream of the recording position when viewed from the recording medium transport direction, and for discharging the recording medium toward a discharge port (not shown). Reference numeral 42 denotes a spur provided corresponding to the paper discharge roller 41, which presses the paper discharge roller 41 via the recording medium to generate a conveyance force of the recording medium by the paper discharge roller 41. Reference numeral 43 denotes a release lever for releasing the urging of the feed roller 39, the pressing plate 45, and the spur 42 when setting a recording medium or the like. Reference numeral 45 denotes a pressing plate for suppressing the floating of the recording medium in the vicinity of the recording position and ensuring the state of close contact with the platen roller 33.

In this embodiment, an ink jet recording head that performs recording by discharging ink is employed as a recording head. Therefore, the distance between the ink discharge port forming surface of the recording head and the recording surface of the recording medium is relatively small, and the distance must be strictly controlled to avoid contact between the recording medium and the discharge port forming surface. The arrangement of the holding plate 45 is effective. Reference numeral 47 denotes a scale provided on the presser plate 45, and reference numeral 49 denotes a marker provided on the carriage 11 corresponding to the scale. The print position and the set position of the recording head can also be read by these. Reference numeral 51 denotes a cap formed of an elastic material such as rubber facing the ink discharge port forming surface of the recording head at the home position, and is supported so as to be able to come into contact with and separate from the recording head. This cap 51
It is used as an ink receiving member at the time of protection of a recording head at the time of non-recording or the like, and at the time of recovery processing of the recording head ejection.

In the present specification, the “ink receiving member” is not limited to the above-mentioned cap, and any form can be used as long as it can receive ink discharged from the recording head.

In the present specification, the term “ejection recovery processing” refers to ejecting ink from all ejection ports by driving an energy generating element provided inside the ink ejection ports and used for ink ejection, or using a cap to eject ejection ports. This is a process for removing the cause of ejection failure, such as bubbles and dust, and ink that is thickened and becomes unsuitable for printing, by applying a suction force while covering the formation surface.

Reference numeral 53 denotes a pump that acts as a suction unit for forcibly discharging the ink, and is a deriving unit that is used to suction the ink received by the cap 51 during the discharge recovery process by the forced discharge and the discharge recovery process by the preliminary discharge. It is. Reference numeral 55 denotes a waste ink storage unit for storing the waste ink sucked by the pump 53, and reference numeral 57 denotes a tube communicating the pump 53 with the waste ink storage unit 55. Reference numeral 59 denotes a blade for wiping the ejection port forming surface of the recording head, which protrudes toward the recording head and moves between a position for performing wiping in the process of moving the head and a retracted position not engaging with the ejection port forming surface. Supported as possible. 61 is a motor, 63
Is a cam device for receiving power transmitted from the motor 61 and driving the pump 53 and moving the cap 51 and the blade 59, respectively.

Next, the details of the above-described head cartridge 9 will be described.

FIG. 4 is a perspective view showing the appearance of a head cartridge 9 in which an ejection unit 9a and an ink tank 9b forming an ink jet recording head main body are integrated. In the drawing, reference numeral 906e is provided on the carriage 11 when the head cartridge 9 is mounted. The hook is hooked by the hook 13 provided. As is clear from the figure, the pawl 906e is disposed inside the full extension of the recording head. In addition, a positioning abutting portion (not shown) is provided near the ejection unit 9a in front of the head cartridge 9. 906f carriage 11
And a head opening into which a support plate for supporting a flexible substrate (electric connection portion) and a rubber pad is inserted.

5 (A) and 5 (B) are exploded perspective views of the head cartridge shown in FIG. 4, and are of a disposable type in which an ink storage unit as an ink supply source is integrated as described above. Referring to FIG.
Is a heater board formed by forming an electrothermal conversion element (ejection heater) on a Si substrate and wiring such as Al for supplying electric power to the element by a film forming technique. 921 heater board 911
And the corresponding wiring is connected by, for example, wire bonding. Reference numeral 940 denotes a top plate provided with a partition for limiting the ink flow path, a common liquid chamber, and the like. In this example, the top plate 940 is made of a resin material integrally having an orifice plate portion. As shown in FIG. 5 (c), the ejection port forming surface is inclined by a predetermined angle θ with respect to a plane parallel to the recording surface of the recording paper, and has a step 940a near the ejection port. doing. This is performed in accordance with the fact that the flow path in the orifice plate and the flow path behind it form a predetermined angle in order to form a discharge port by irradiating a laser beam from the flow path side provided on the top plate. It was done. In FIG. 5A, reference numeral 930 denotes a metal support, and reference numeral 950 denotes a pressing spring, between which a heater board 911 and a top plate 940 are provided.
When the two are engaged while holding the heater board 911 and the top plate 940 by the biasing force of the holding spring 950.
And crimped. The support 930 includes a wiring board 921.
May be provided by sticking or the like, and may have a positioning reference to the carriage 11 for scanning the head. In addition, the support 930 also functions as a member that radiates and cools the heat of the heater board 911 generated by driving. Reference numeral 960 denotes a supply tank, which functions as a sub-tank that receives ink supply from the ink storage unit 9b serving as an ink supply source and guides ink to a common liquid chamber formed by joining the heater board 911 and the top plate 940. Reference numeral 970 denotes a filter arranged at a position in the supply tank 960 near the ink supply port to the common liquid chamber, and 980 denotes a cover member of the supply tank 960. 900 is an absorber for impregnating the ink,
Located within 9b. Reference numeral 1200 denotes a supply port for supplying ink to the recording element composed of each of the parts 911 to 980, and injects ink from the supply port 1200 in a process before the unit is arranged in the portion 1010 of the ink tank body 9b. This makes it possible to impregnate the absorber 900 with ink. 1100 is a lid member of the cartridge main body, and 1300 is an atmosphere communication port provided in the lid member for communicating the inside of the cartridge with the atmosphere. When the ink filling into the ink storage section 9b via the supply port 1200 is completed, the ejection unit including the parts 911 to 980 is positioned and arranged in the portion 1010. The positioning or fixing at this time can be performed, for example, by fitting a projection 1012 provided on the ink storage portion 9b with a hole 931 provided on the support 930 corresponding to the projection 1012. The head cartridge 9 shown in (B) is completed. Then, the ink is supplied from the inside of the cartridge to the supply tank 960 via the supply port 1200, the hole 932 provided in the support 930, and the introduction port provided on the back surface side in FIG. 5A of the supply tank 960.
After passing through the inside, the liquid flows from the outlet through an appropriate supply pipe and the ink inlet 942 of the top plate 940 into the common liquid chamber. A packing made of, for example, silicone rubber, butyl rubber, or the like is provided at the connection portion for ink communication described above, whereby sealing is performed to secure an ink supply path.

FIG. 6 is an exploded perspective view of the recovery device including the cap 51, the pump 53, the blade 59, the motor 61, the cam device 63, and the like in FIG. Here, 501 is an ink absorber arranged inside the cap 51, 503 is a holding member for holding the cap 51, 505 is attached rotatably around a pin 507, and the cap 51 is moved by a force applied to the pin 507. A cap lever for contacting / separating from the ejection port forming surface of the head cartridge 9. 511 is the cap lever 505
For restricting the rotation range of the cap lever 505 by engaging with the end 509 of the cap lever 505. Reference numeral 513 denotes a jig having a hole into which the pin 507 of the cap lever 505 is fitted, and is used to attach the cap lever 505 to a support 515 provided on the pump 53. Reference numeral 516 denotes a fastening member for securing the attached state. Reference numeral 517 denotes an action portion for applying a force for abutting the discharge port forming surface to the cap 51, and is engaged with substantially the center of the rear side of the cap 51. This action section has a suction port 517A for sucked ink, and the inside of the cap lever 505,
An ink flow path is formed inside the pin 507, inside the jig 513, and inside the support portion 515, respectively. And pump 53
When the ink exerts a suction force, ink is introduced into the pump 53 through these flow paths as indicated by arrows in the figure. 519 is a shaft protruding at the center of the end face of the pump 53, 522 is a pump support plate for holding the shaft 519 and enabling the pump 53 itself to rotate,
The rotational power is applied to the cap lever 505 via the support 515, and the cap 51 advances and retreats accordingly. Reference numeral 521 denotes a drain ink seal that turns an ink flow path passing through a shaft 519 of the pump 53 at a right angle. Reference numeral 523 denotes a discharge ink seal that supports the discharge ink seal 521 and further forms an ink flow path to the discharge ink tube 57. Cap. An ink flow path is formed inside the shaft 519, the discharged ink seal 521, and the discharged ink cap 523, and the ink sucked by the pump 53 is discharged through the flow path through the tube 57 as shown by an arrow in the drawing. It is introduced into the ink storage unit 55. 525 is a piston of the pump 53, 527 is its shaft, 529 is packing, and 531 is a cap of the pump 53. A pin 533 is attached to the piston shaft 527 and receives a force for operating the piston 525. Reference numeral 535 denotes a blade lever to which the blade 59 is attached. The blade lever 535 is rotatably supported around a shaft protruding from the end face of the pump 53, and causes the blade 59 to protrude or retreat toward the recording head with the rotation. Reference numeral 537 denotes a spring that applies a rotating force to the blade lever 535 in a direction in which the blade 59 projects. Also, 539 is a cap 53 for the pump 53 itself.
Is a spring that gives a rotating behavior in the direction toward the recording head. A gear train 541 transmits the rotation of the motor 61 to the cam device 63. The cam device 63 includes an engaging portion provided on the pump 53.
A cam 547 for engaging and rotating this 545, a cam 549 for engaging the pin 533 provided on the piston shaft 527 of the pump 53 to operate the pump, and a cam provided for the blade lever 535 Cam 5 for engaging and rotating joint 551
53, and a cam 557 that engages with a switch 555 for detecting the home position of the cam device 63. The operation of these cams will be described later.

FIGS. 7A and 7B show a configuration example of the cap 51. FIG.

FIG. 7B is a cross-sectional view taken along line MM of FIG. 7A.

In FIGS. 7A and 7B, reference numeral 51a denotes a rib, and reference numeral 51b denotes a peripheral portion of the rib.

The cap 51 according to the present embodiment is formed of a rubber-like elastic body in order to improve the close contact with the recording head portion of the head cartridge 9, and at the time of capping, the orifice of the top plate 940 has a pressing force of about 60 to 80 g. It is pressed against the plate. In the cap 51, the ink suction port 561 is
The ink flow path 563 is opened at the lower part in the vertical direction and faces the ink introduction port 517A provided in the action part 517 of the cap lever 505. In addition, the suction port 561 is
Is not completely covered by As a result, even if the ink flows downward due to gravity, the ink is sucked from the suction port 561 provided below, so that the amount of ink remaining in the ink absorber 501 is extremely small, and deterioration due to solidification is greatly reduced. The life of the ink absorber or the cap 51 to which the ink absorber is attached can be extended.

FIG. 8 is a cam chart of the recovery device.
Take 9 rotation angles, switch 555, cap 51, pump
53, the state of the blade 59 is shown.

FIG. 9 is a diagram showing the position of the piston 525 in the pump 53 in each state.

FIG. 10 is a view showing the cap in the S direction scanning of the head ejection port forming surface 9h of the head cartridge 9 referred to in FIG.
FIG. 7 is a diagram showing a positional relationship between 51 and a blade 59.

FIG. 11 is a block diagram illustrating a configuration example of a control system of the inkjet recording apparatus according to the present embodiment.

FIG. 12 is a flowchart illustrating a recording head cleaning operation performed by the recovery system unit.

The functions of the recovery system unit of this embodiment will be described with reference to FIGS.

The state in FIG. 8 is the home position of the cam 549, and is a standby state of the recovery device during printing. The switch 555 is ON, the cap 51 is separated from the head discharge port forming surface (hereinafter referred to as an “open state”), the pump 53 is at the top dead center, and the blade 59 is in the OFF state, that is, at a position where it does not engage with the head. Have been evacuated. The next state is a capping state, which covers and protects the head ejection port forming surface in a state such as when the printer is not used. At this time, the switch 555 is OFF, the cap 51 is joined to the head discharge port forming surface (closed), and the pump 53 is at the top dead center.
The blade is off.

A further state is a state in which pumping has been completed. At this time, the switch 555 is turned on, the cap 51 is closed, and the pump 53 is in a state where the valve is fully opened and does not reach the bottom dead center. The blade 59 is in the OFF state.

Is a state in which the cap 51 is opened after the pumping is completed, and the small-vacuum suction for simultaneously taking the ink filled in the cap 51 and the cap lever 505 into the pump 53 is completed. In this state, the operation is stopped for one second as a stop period for promoting the discharge of ink (see step 9 in FIG. 12). At this time, switch 555 is set to O
N, the cap 51 is about half open, the pump 53 is at the bottom dead center, and the blade is in the OFF state. In the present invention, the recording head is retracted to the blade OFF position in this state.

The next state will be described first. This is a preparation position to start idle suction for discharging the ink filled in the pump 53 to the discharge ink tank side by pumping. The switch 555 is ON, the cap is open, and the pump 53 is slightly below the top dead center. The blade is in the OFF state.

And are the stop positions when the air suction and the hollow suction are performed, respectively. In both cases, switch 555 is ON,
Although the cap is open and the blade is in the OFF state, the state of the pump 53 is at the bottom dead center side but not completely lowered. At each of these stop positions, the stop period at the stop position is much shorter than the stop period, and is preferably smaller than 1 second, preferably 0.5 second or less, and is set to 0.3 second in this embodiment. This stop period may be a period from the stop of the elastic body that blocks the suction port of the piston until the vibration stabilizes. In any case,
By the stop period, the suction efficiency of the idle suction operation can be made sufficient, and the cause of the backflow of the ink can be largely suppressed.

Is a state when wiping is performed. The switch 555 is ON, the cap is open, and the pump is at top dead center. The blade is in the ON state, and the carrier on which the head is mounted moves in this state, so that the wiping of the head discharge port forming surface can be performed.

In FIG. 9, the piston 525 is located in the pump.
Indicates a state at the bottom dead center. In the space within the pump 53, pumping works by the negative pressure created by the space to the left of the piston 525. Reference numeral 531 denotes a communication port for transmitting the negative pressure to the cap 51. Piston in state
It can be seen that 525 has passed this contact 531 and has proceeded further to the right. Here, the piston 525 is pressed by the piston shaft flange of the 527 from the left side and is in close contact with it,
The generated negative pressure is transmitted to the cap 51 without leakage. The ink accumulated on the right side of the piston shaft 525 is pushed out to the waste ink tank.

Indicates a state at the top dead center. Note that the piston 525 is located on the left side of the communication port 531 and the communication port 531
Is not closed. That is, in this state, the cap 51
Is in air communication.

FIG. 8 shows the state of the pump 53 at the time of referring to FIG. The piston 525 has passed the communication port 531 and is slightly to the right.

FIG. 8 shows the state at the time of FIG. 8, and the sky suction and the hollow suction are executed by reciprocating between this state and the state.

Is the state when the hollow suction has been completed. It should be noted here that the piston 525 is stopped immediately after passing over the communication port 531. If it reaches the bottom dead center, the time during which the communication port 531 cannot be closed when returning to the top dead center or the empty suction preparation position becomes long. At this time, a slight gap is formed between the piston shaft flange 527a and the piston 525 so that a positive pressure is not generated in the left space, and the piston 525 is configured to communicate with the right space. However, a slight positive pressure may be generated due to resistance due to grease or the like existing in the flow path, which may cause a reverse flow. As described above, the backflow phenomenon to be considered in the present embodiment is such that, when the space on the right side of the pump becomes a positive pressure due to the movement of the piston 525 with the communication port 531 being open, for example, the piston 525 becomes idle from top dead center. Occurs when going to the ready position. The backflow phenomenon is
When the space on the left side of the pump becomes positive pressure due to the movement of the piston 525 with the communication port 531 being open, for example, the piston
Occurs when 525 returns from the bottom dead center to the empty suction preparation position. Therefore, the control of the relative position between the recording head and the ink receiving member, which is preferable as an additional configuration of the present invention, is preferably performed at least when the piston is returned after the suction operation and when the reciprocation of the piston is reversed.

Head ejection port forming surface of head cartridge 9 in FIG.
The positional relationship diagram of 9h is expressed based on the position where the head ejection port forming surface 9h of the head cartridge 9 is in front of the cap 51 of the ejection recovery system, that is, the capping position (A). Here, the number of steps described in the figure represents the driving amount of the pulse motor for S-direction scanning drive. 6/360 inch = 1/60 inch = 0.423 mm per step. When performing the wiping operation, first, the head discharge port forming surface 9h is set to the blade ON position (B) as shown in 9h (B).
The blade 59 is advanced to the position 59a by turning on the blade in the discharge recovery device. Then, the wiping is executed by moving the head discharge port forming surface 9h to the blade OFF position (C) as shown in 9h (C). At this time, since the blade 59 is formed from a rubber-like elastic body, unnecessary ink adhering to the surface of the head discharge port forming surface 9h is eliminated while deforming as shown in FIG. 59b. When the head ejection port forming surface 9h moves to the blade OFF position (C), the blade 59 is retracted to the original position.

In the embodiment of the present invention, the position where the recording head is retracted is the blade OFF position.

FIG. 11 is a block diagram showing a configuration example of a control system of the printing apparatus having the above configuration.

The cap position and the movement position of the carriage 11 can be known based on the detection of the recovery system home sensor 65 and the carriage home sensor 67. In the figure, 1000 constituting a microcomputer 999 executes a control procedure to be described later to generate a control signal, and an MPU 1001 for controlling each unit is a ROM storing programs and the like corresponding to the control procedure. Used as a work area when executing control procedures
RAM. 1003 is a timer for measuring time.

The flowchart in FIG. 12 shows an example of the ejection recovery processing procedure executed by the recovery unit under the control of the MPU 1000 in FIG.

This procedure starts with a capping state as shown in FIG. 8 (step S1). Then, pumping is executed by moving to the state (step S3), and a stop for 3 seconds is performed so that ink suction is sufficiently performed in that state (step S5). In step S7, suction of small air is performed simultaneously with opening of the cap (step S7), and the operation is stopped for one second so that ink is taken in the cap 51 and the cap lever 505 (step S9). Next, after performing the preliminary ejection (step S11), before starting the idle suction operation, the print head is retracted to the blade OFF position referred to in FIG. 10 (step S13). As a result, the recording head and the cap have a positional relationship in which they do not face each other. Next, idle suction for discharging the ink filled in the pump 53 is performed. The process first moves to the idle suction preparation position (step S15), and then reciprocates three times between the hollow suction stop positions including the stop period of 0.3 seconds (step S20) (steps S17 to S23).
However, the reversal of the idle suction preparation position is executed immediately without stopping.

Next, the air is moved from the same empty suction preparation position to the empty suction stop position, which is the bottom dead center (step S25), and a 0.3 second stop period is simultaneously executed (step S26), whereby the empty suction is performed. The ink is sufficiently pushed out to the waste ink storage unit side. Move to the next position (Step S27), move the print head to the blade ON position (Step S29), turn the blade ON at the position (Step S31), and move the print head to the blade OFF position to execute wiping. (Step S33).
Finally, the blade is turned off at the position (step S35), the recording head is returned to the capping position (step S37), and capping is performed (step S39).

FIGS. 13 (a) and 13 (b) are flowcharts showing the print control procedure of the present embodiment. The main operation is a preliminary ejection. FIG. 13 (b) is for executing the idle suction in the flowchart of FIG.

Predischarge (a) is performed immediately before printing, and thereafter predischarge (b) is performed at 30-second intervals. Further, the timer T ₁ is used for the integration of the 30 second interval. T ₁ is no print signal 5
If the capping (c) is started for more than a second, the operation is stopped, and the time during capping is not counted in the interval of 30 seconds. In addition, capping (c) is 60
In the case of more than one second, the control procedure returns to the preliminary discharge (a), and performs the preliminary discharge before the printing after the cap is opened. The preliminary ejection is performed in the cap. Therefore, when the preliminary ejection is repeatedly performed, it is necessary to perform idle suction in order to take the ink that has accumulated in the cap due to the preliminary ejection into the drain ink tank side. This is the empty suction in FIG. 5-d. Basically, idle suction is performed between pages that are not printed. Preliminary ejecting counter N ₁ after one page printing 7
In the case described above, the idle suction (d) is performed.
However, if N ₁ is also in the middle page during printing it becomes 15 or more, i.e., performs the idle suction (e) a in document requiring a long printing time. At the end of printing, idle suction is always performed. Next, wiping will be described. This is to clean the head face surface on which the ink has spilled after printing, and this is performed after one page and all printing are completed.

FIG. 14 to FIG. 14 show a suction pump used for processing ink discharged from the recording head, which is provided with a cylinder provided with a suction port for sucking the discharged ink, while contacting an inner wall of the cylinder. Operating, opening and closing the suction port with the operation, and a piston for generating a negative pressure for the suction, wherein the suction port and the piston are at the top dead center When the suction port is communicated with the inside of the pump, and the piston has a relative positional relationship of increasing a region facing the suction port as the piston moves from the top dead center to the bottom dead center. 2 shows a featured suction pump.

The following can be considered as other causes of the backflow.

In the state shown in FIG. 9, the suction port 531 is not closed by the piston 525 as described above,
It is open to the atmosphere, that is, communicates with the space B shown in the figure. Since the space B is always in communication with the discharge ink tank side, the pressure generally does not increase. However, the flow path to the waste ink tank is very narrow in an actual device due to space limitations. As a result, when the piston is moved toward the bottom dead center within a relatively short time, a slight pressure rise occurs in the space B. For this reason, when the suction port 531 and the space B are in communication for a long time, a positive pressure is transmitted to the cap side until the piston 525 completely closes the suction port 531. it is conceivable that. This embodiment is characterized by solving this. That is, the present invention provides a suction pump capable of greatly reducing the backflow of ink or air once sucked, and an ink jet recording apparatus using the pump as an ejection recovery device.

According to the above configuration, the positional relationship between the shape of the piston and the suction port provided in the cylinder is such that the suction port is not closed even when the piston is at the top dead center, and the piston starts to move toward the bottom dead center. At the same time, by setting the positional relationship to close the suction port, during the idle suction operation, for example, the suction port is closed when the piston is slightly shifted from the top dead center to the bottom dead center side, and from this state It is possible to control the operation of the piston so as to generate a negative pressure, and it is possible to realize an idle suction operation in which the backflow of the ink or air once sucked is greatly reduced.

In the above-described embodiment, the recording head slides rightward toward the apparatus to escape, but is not limited to this direction. It is assumed that the recording head retreats to the left side or away from the apparatus toward the apparatus. There is no problem at all.

Further, in the above-described embodiment, in order that the recording head and the cap do not face each other during the process of guiding the ink received by the cap discharged from the recording head to the waste ink storage unit by the deriving unit, Although the operation of retracting the recording head to the OFF position of the blade was performed, in this specification, the mode of "controlling the relative position of the recording head and the ink receiving member" is not limited to this, and the recording head may be turned off of the blade. The cap may be moved to a position that is not opposed to the cap at a position other than the position.Also, while the position of the recording head is locked, the cap side is displaced conversely so that the recording head does not face the recording head. You may. Further, both the recording head and the cap are displaced,
The two may not be in a facing relationship.
Further, when the recording head and the cap are in a positional relationship where they do not face each other, by locking only the recording head or only the cap, or by locking the positions of both the recording head and the cap, it is possible to prevent the two from facing each other. Good. However, the mode in which only the recording head described in the above example is displaced to a position that does not face the cap involves only a part of the ejection recovery processing procedure executed by the recovery system unit and involves other mechanical changes. It is particularly suitable because it can be performed without any modification. In the above example, as shown in FIG. 12, the setting is made such that the suction operation of the recording head is performed in step 13 after the suction of small air in step 7 is performed. This is a phenomenon that occurs after ink is taken into the pump. Therefore, in the present embodiment, the recording head and the cap are arranged so that the recording head and the cap do not face each other during the process of guiding the ink discharged from the recording head and received by the cap to the waste ink storage unit by the deriving unit. The step of controlling at least one of the steps may be performed before the ink jumps out of the cap due to the backflow of the ink during the step.If this condition is satisfied, the step may be performed after the step is started. There is no particular limitation on the time at which the process is performed as long as the above conditions are satisfied. Therefore, the control signal for retreating the recording head, etc. sent from the MPU 1000 shown in FIG. 11 is sent before the ink jumps out of the cap due to the backflow of the ink, and the control is executed based on this control signal. Good.
Therefore, for example, in a case where the ejection of the ink from the cap due to the backflow of the ink occurs only after the idle suction step is performed a plurality of times, the control step does not necessarily need to be performed for each idle suction step, and is performed multiple times. The idle suction process may be performed only when the ink pops out.

In addition, the present invention is a recording head of the bubble jet method proposed by Canon Inc., especially in the ink jet recording method, which brings about an excellent effect in the recording apparatus. This is because high definition can be achieved.

Regarding the typical 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 the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, heat energy is generated in the electrothermal transducer, and the recording head This is effective because a film in the liquid (ink) corresponding to the driving signal can be formed one by one by causing film boiling on the heat acting surface. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,434,262 are suitable. Further, when the conditions described in 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 ejection port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a thermal action 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 portion is arranged in a bending region, is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge section of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy. The effect of the present invention is effective even if the configuration is based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed 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 with a serial type printer as in the above example, a recording head fixed to the main unit or attached to the main unit enables electrical connection with the main unit and supply of ink from the main unit. The present invention is also effective when a replaceable chip-type recording head or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add recovery means for the print head, preliminary auxiliary means, and the like provided as a configuration of the printing apparatus in the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, and printing Performing a preliminary ejection mode for performing another ejection is also effective for performing stable printing.

Regarding the type or number of print heads to be mounted, for example, in addition to one provided for single color ink, a plurality of print heads are provided corresponding to a plurality of inks having different print colors and densities. May be used. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also extremely effective for an apparatus provided with at least one of full colors by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink that solidifies at or below room temperature and softens or liquefies at room temperature, or the ink itself in an inkjet method. In general, the temperature is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. I just need. In addition, positively prevent the temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or use an ink that solidifies in a standing state to prevent evaporation of the ink. In any case, the ink liquefies by the application according to the recording signal of the thermal energy,
The present invention is also applicable to a case where an ink having a property of being liquefied for the first time by thermal energy, such as an ink from which a liquid ink is ejected and an ink which starts solidifying when reaching a recording medium, is used. In such a case, the ink
As described in JP-A-54-56847 or JP-A-60-71260, while being held as a liquid or solid substance in a porous sheet concave portion or through hole, an electrothermal converter is used. It is good also as a form which opposes. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as an embodiment of the ink jet recording apparatus according to the present invention, in addition to the above-described one provided as an image output terminal of an information processing device such as a word processor or a computer as an integral or separate unit, a copying apparatus combined with a reader or the like Further, a facsimile apparatus having a transmission / reception function may be employed.

[Effects of the Invention] As described above, according to the present invention, there is an advantage that the backflow of the liquid, particularly the ink during the idle suction can be effectively prevented, and the pump mechanism can be downsized.

[Brief description of the drawings]

FIG. 1 is a flowchart of a main part of one embodiment of the present invention, FIG. 2 is a perspective view showing a configuration of a word processor as one embodiment of a device to which the present invention is applied, and FIG. FIG. 4 is a perspective view showing an embodiment of an ink jet recording apparatus, FIG. 4 is an external perspective view of a head cartridge 9 in FIG. 3, and FIGS. 5A and 5B are exploded views of the head cartridge shown in FIG. FIG. 5 (C) is a perspective view showing a configuration example of the recording head top plate in FIG. 5 (A), and FIG. 6 is an exploded perspective view of the ejection recovery mechanism shown in FIG. 7 (A) and 7 (B) are a front view and a side sectional view of the cap according to the present embodiment. FIG. 8 is an explanatory view showing a contour curve of a cam for operating each part of the ejection recovery mechanism. FIG. 9 to FIG. 9 are explanatory diagrams for explaining the operation of the pump according to this embodiment. FIG. 10 is a diagram showing a scanning position relationship of the head cartridge according to the present embodiment, FIG. 11 is a block diagram showing a configuration example of a control system of the ink jet recording apparatus according to the present embodiment, and FIG. FIG. 13 (a) is a flowchart showing an example of the operation procedure.
(B) is a recording flowchart of an embodiment of the recording apparatus of the present invention,
FIG. 14 is an explanatory view of another embodiment of the pump configuration of the present invention. 9 Head cartridge 9a Discharge unit 51 Cap 53 Pump 999 Microcomputer

Claims (12)

(57) [Claims] 1. A suction device comprising: a cap for contacting a recording head provided with a discharge port for discharging a liquid and covering the discharge port; a cylinder communicating with the cap, and a piston reciprocating in the cylinder. A recovery method for a liquid discharge recording apparatus, comprising: a pump; and moving the piston in a state in which the inside of the cap is not communicated with the atmosphere, thereby performing suction from the discharge port. When the piston is moved a plurality of times from the top dead center side to the bottom dead center side while communicating with each other, when performing idle suction for discharging waste liquid from within the suction pump, the bottom dead center side of the piston is inverted. A recovery method for a liquid discharge recording apparatus, wherein the piston is stopped at a position for a predetermined period. 2. The method according to claim 1, wherein said cylinder has a suction port communicating with said cap in a reciprocating range of said piston. 3. The recovery method for a liquid discharge recording apparatus according to claim 2, wherein the movement start position of the piston in the idle suction is between a top dead center and the suction port. 4. The recovery method for a liquid ejection recording apparatus according to claim 2, wherein the reverse position of the piston at the bottom dead center side in the idle suction is near the suction port. 5. The piston is not stopped at an inverted position on the top dead center side of the piston in the idle suction.
5. The recovery method for a liquid ejection recording apparatus according to any one of 4. 6. A first movement from the top dead center side to a bottom dead center side of the piston in the idle suction to the vicinity of the suction port, and the second movement is performed before the vicinity of the suction port. The method for recovering a liquid ejection recording apparatus according to claim 2, wherein: 7. The method according to claim 1, wherein a volume from a top dead center to a bottom dead center of the suction pump is 1 cc or less. 8. The suction pump according to claim 1, wherein said suction pump has a piston shaft for reciprocating said piston, and waste liquid in said suction pump is discharged through a gap between said piston and said piston shaft. The method for recovering a liquid discharge recording apparatus according to any one of the above. 9. The recording head according to claim 1, further comprising: an electrothermal transducer for generating thermal energy used for discharging the liquid from the discharge port by causing film boiling of the liquid.
9. The method for recovering a liquid discharge recording apparatus according to any one of claims 8 to 8. 10. A state in which the inside of the cap is communicated with the atmosphere, the cap is separated from the recording head or
Alternatively, the recovery method of the liquid ejection recording apparatus according to any one of claims 1 to 9, which is formed by opening a valve of the cap. 11. The recording apparatus according to claim 1, wherein said recording head and said cap are held in a non-opposed state during said idle suction.
The recovery method of the liquid ejection recording apparatus according to any one of the above. 12. The liquid according to claim 2, wherein, in the idle suction, at least a part of the piston starts closing the suction port as soon as the piston starts moving toward the bottom dead center. A recovery method for the ejection recording apparatus.