JP2012096492A - Inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of recovery treatment by making a prescribed negative pressure preferably act on a face at suction recovery treatment, and to prevent the lowering of the efficiency of the recovery treatment resulting from a failure of a part and a waste of ink, in an inkjet recording device which has a cap for sealing a recording head arranged at a discharge port, a pump connected to the cap and generating a suction force, and a switch valve arranged between the cap and the head, reduces the pressure of a pressure chamber by driving the pump while the valve is closed, and performs the treatment for sucking the ink from the discharge port by opening the valve while the face is sealed by the cap.SOLUTION: The device includes: determining whether a rise of the pressure of the pressure chamber accompanied by the opening of the valve is in a first case that the rise is normal, or in a second case that the rise is extremely abrupt, or in a third case that the rise is extremely slow; issuing an alarm when the second case is determined; and performing the treatment once again when the third case is determined.

Description

  The present invention relates to an ink jet recording apparatus, and in particular, ink jet recording having a recovery processing mechanism that involves a process of sucking ink from a recording head in order to maintain or recover the ink discharging operation of a recording head that discharges ink in a good state. It relates to the device.

  In an ink jet recording apparatus, thickened ink or dust accumulates in the nozzles of the recording head or around the discharge port during recording or standby, or bubbles accumulate in the liquid chamber in the recording head to which the nozzles communicate or in the vicinity of the nozzles. As a result, the ejection failure and the recording disturbance occur. Therefore, in the ink jet recording apparatus, there is a process for forcibly discharging the ink in the recording head from the discharge port to remove thickened ink, dust, bubbles, and the like that cause ejection failure (nozzle clogging in extreme cases). Done. As one form of such forced discharge, a suction member is provided which provides a cap member capable of capping the surface (discharge surface) of the recording head provided with the discharge port, and drives the pump in the capped state to apply a suction force to the discharge surface. Some perform recovery actions. In this method, a cap member that forms a sealed space is joined on the ink ejection surface of the recording head, and ink is sucked from the ejection port by applying a pressure (negative pressure) less than atmospheric pressure to the sealed space using a pump. Thus, the ink inside the ejection port is forcibly discharged.

  In Patent Document 1, an open / close valve and a pressure chamber are provided between a cap member and a pump, and the valve is opened by driving the pump while the valve is closed, and then opening the valve. A technique for applying the negative pressure to the discharge surface is disclosed. According to this technique, since the negative pressure or suction force in the pressure chamber can be instantaneously applied to the ejection surface, the amount of waste ink can be reduced.

  However, in the conventional ink jet recording apparatus, the user generally performs image formation after performing the suction recovery process, and confirms the effect of the suction recovery process, that is, confirms that the ink ejection state has been recovered to a good state. Is. If the effect is not confirmed, suction recovery is performed again, and image formation and confirmation are performed. Therefore, since the operations of suction recovery, image formation and confirmation are repeated until the effect is confirmed, it cannot be said that the efficiency is high, and the ink consumption increases. Also, if parts such as pumps and cap members are broken for some reason, the image formation and confirmation operations are repeated without obtaining a sufficient suction recovery effect. This will waste ink.

  In the suction recovery method disclosed in Patent Document 1, a valve, a pressure chamber, and a pump are connected by a connecting member such as a flexible tube to form a suction path, but the valve is closed to drive the pump. If the pressure chamber has a predetermined negative pressure, the connecting member is deformed (collapsed). For this reason, even if the valve is opened, there may be a case where a sufficient negative pressure that should act on the discharge surface cannot be obtained.

JP 10-2111720 A

  The present invention has been made to solve the above problems. That is, the present invention improves the recovery processing efficiency by allowing a predetermined negative pressure to preferably act on the ejection surface during the suction recovery processing, and reduces the recovery processing efficiency due to component failure and wastes ink. The purpose is to prevent.

For this purpose, the present invention provides a cap for sealing the surface of a recording head provided with an ejection port for ejecting ink;
A pump connected to the cap to generate a suction force;
A pressure chamber provided in a connection path between the cap and the pump, and decompressed as the pump is driven;
A valve provided in a connection path between the pressure chamber and the cap to open and close the valve;
The pressure chamber is depressurized by driving the pump with the valve closed, and the ink is sucked from the discharge port by opening the valve with the surface sealed by the cap. Control means;
With
The control means determines whether the pressure chamber pressure increase accompanying the opening of the valve is normal, a second case that is too rapid, or a third case that is too slow. When the second case is determined, a warning is given, while when the third case is determined, the process is performed again.

  According to the present invention, a predetermined negative pressure can be preferably applied to the ejection surface during the suction recovery process, thereby improving the recovery process efficiency and reducing the recovery process efficiency due to component failure and the ink. Waste can be prevented.

1 is a schematic diagram illustrating an embodiment of an inkjet recording apparatus to which the present invention is applicable. FIG. 2 is a block diagram illustrating a configuration example of a control system of the ink jet recording apparatus of FIG. 1. FIG. 2 is a schematic diagram for explaining a configuration example of a suction recovery system in the ink jet recording apparatus of FIG. 1. It is a perspective view which shows the external appearance of the suction mechanism in the inkjet recording device of FIG. FIG. 5 is a perspective view showing a part of the suction mechanism in a broken state in order to show a configuration of a week side of the suction pump in the suction mechanism of FIG. 4. FIG. 5 is a perspective view showing a part of the suction mechanism in a broken state in order to show the configuration of a week side of the recovery valve in the suction mechanism of FIG. 4. FIG. 6A is a diagram illustrating a surface obtained by breaking the suction mechanism on a vertical plane including a one-dot chain line in FIG. 6 from the direction of arrow VIIa, and FIG. FIG. 6 is a flowchart showing a recovery processing procedure of the ink jet recording apparatus according to the embodiment of the present invention. It is a graph which shows the value of the pressure sensor 206 detected at the time of pressure chamber pressure reduction in the process of the suction recovery process performed in the recovery process procedure of FIG. (A), (b) and (c) is a graph which shows the value of the pressure sensor detected at the time of ink attraction | suction in the process of a recovery process. It is a graph which shows the pressure change for demonstrating the process performed by this embodiment when the state of FIG.10 (c) arises. It is a flowchart which shows the recovery processing procedure of the inkjet recording device which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Mechanical structure)
FIG. 1 is a schematic view showing an embodiment of an ink jet recording apparatus to which the present invention can be applied. An ink jet recording apparatus (hereinafter also referred to as a printer) 10 is connected to a host apparatus 12 in the form of a personal computer, which is an external apparatus that serves as a supply source of image data. The printer 10 has recording heads 22K, 22C, and 22M for ejecting black (K), cyan (C), magenta (M), and yellow (Y) inks in order to perform full-color recording on the recording medium P. And 22Y are mounted. These recording heads 22K, 22C, 22M and 22Y are so-called line heads having ink discharge ports or nozzles arranged in a predetermined density and in a predetermined range in the width direction of the recording medium P (direction orthogonal to the medium conveying direction A). It is in the form. The predetermined range is slightly longer than the maximum effective recording width (the length in the direction perpendicular to the paper surface) on the recording medium that can be printed by the printer 10. Needless to say, the number of recording heads, the type of color tone (color, density), the type of liquid to be ejected, etc. are merely examples. Further, in the following description, when the color tone is not specified, the recording head is generally referred to by reference numeral 22.

  The recording head 22 is held by a holding unit (not shown) and can be moved up and down in the vertical direction (B direction) together with the holding unit. Further, the recovery unit 40 having the cap 50 corresponding to each recording head 22 is held so as to be movable in the horizontal direction (the direction A and the direction opposite to the A direction).

  At the time of non-printing such as in a storage state or during printing standby, the surface (discharge surface) 22S of the recording head 22 in which the discharge ports are formed is in a state where a cap 50 is applied. If the discharge surface of the recording head is exposed to the atmosphere during non-printing, the ink solvent near the discharge port may evaporate, causing ink to thicken or solidify, or dust may adhere to it, resulting in discharge failure. Because there is. In addition, the recording head that ejects ink desirably performs a recovery process for maintaining or recovering the ink ejection state in a stable state, and the capping state enables such a recovery process by the recovery unit 40. It is also a state to do. As will be described later, the recovery process according to the present embodiment includes a suction recovery operation in which ink is sucked from the ejection port by applying a negative pressure to the space in the cap or the nozzle in the capping state. Further, it may include a preliminary ejection operation for causing the recording head to perform a preliminary ejection operation toward the cap before printing. Furthermore, the operation of wiping the ejection surface of the recording head with a wiper blade made of an elastic member such as rubber can be included. The recovery unit 40 has components for performing these operations.

  When shifting from the capping state to the printing operation, the holding unit or the recording head 22 is once raised, and then the recovery unit 40 is retracted to the left in FIG. 1, and is further opened in the opening provided between the caps 50 of the recovery unit 40. The recording heads 22 face each other. Then, the holding unit or the recording head 22 is lowered, the recording head 22 protrudes downward from the opening between the caps, and is set to a position facing the recording medium P with a predetermined gap. Then, the recording head 22 is fixed at the position, the recording medium P is conveyed in the A direction, and the recording head 22 is caused to perform an ink ejection operation in the process, thereby performing a printing operation for recording an image. When the printing operation is completed and the state is set to the non-printing state, the reverse operation may be performed.

  The recording medium P in roll paper form is supplied from the supply unit 24 and is conveyed in the direction of arrow A by a conveyance mechanism 26 incorporated in the printer 10. The transport mechanism 26 includes a transport belt 26a for placing and transporting the recording medium P, a transport motor 26b for rotating the transport belt 26a, and a roller 26c for applying tension to the transport belt 26a. Of course, the recording medium P is not limited to the form of roll paper, but may be of cut paper, fanfold paper, or the like.

  In the configuration of FIG. 1, when an image is formed on the recording medium P, the recording start position of the recording medium P that is being conveyed reaches under the recording head 22K for K, and then is based on print data (image data). Thus, K ink is selectively ejected from the ejection ports of the recording head 22K. Similarly, each color ink is ejected in the order of the recording head 22C, the recording head 22M, and the recording head 22Y to form a color image on the recording medium P.

  In addition to the above-described units, the printer 10 includes ink tanks 28K, 28C, 28M, and 28Y that store the inks of the respective colors that are supplied to the recording heads 22K, 22C, 22M, and 22Y. 28). Further, a pump mechanism for forcibly discharging ink from the discharge port into the cap is also provided.

(Control system configuration)
FIG. 2 is a block diagram illustrating a configuration example of a control system of the ink jet recording apparatus of FIG. Recording data and commands transmitted from the host device 12 are received by the CPU 100 via the interface controller 102. The CPU 100 is an arithmetic processing unit that performs overall control such as reception of recording data of the printer 10, recording operation, handling of the recording medium P, and the like. In the CPU 100, after analyzing the received command, the image data of the component of the print data is bitmap-developed in the image memory 106, further divided into rasters, and data to be recorded by each recording head is allocated.

  As a processing operation before printing, the CPU 100 drives the capping motor 122 and the head up / down motor 118 via the output port 114 and the drive unit 116, and the recording head 22 is separated from the cap 50 to the recording position (image forming position). ) To move. Subsequently, the CPU 100 drives a roll motor (not shown) via the output port 114 and the drive unit 116, and drives the transport motor 26b and the like. The capping motor 122 serves as a drive source for moving the recovery unit 40 in the horizontal direction, and the head up / down motor 118 serves as a drive source for moving the recording head 22 up and down. The roll motor serves as a drive source for supplying the recording medium P, and the transport motor 26b serves as a drive source for transporting the recording medium P to the recording position by the recording head 22.

  In order to determine the timing at which ink starts to be ejected onto the recording medium P conveyed at a constant speed, the front end position of the recording medium P is detected by a front end detection sensor. Thereafter, in synchronism with the conveyance of the recording medium P, the CPU 100 sequentially reads out the data sent from the image memory 106 to the corresponding recording head 22, and the read data is sent to each recording head 22 via the recording head control circuit 112. Forward.

  The printer 10 is provided with a sensor group 130 for detecting a state that is a precondition for performing a required operation. The sensor group 130 includes a pressure sensor, which will be described later, in addition to the above-described tip detection sensor and temperature sensor. Detection signals from these sensors are transmitted to the CPU 100 via the input port 132. The CPU 100 controls each unit based on the processing program stored in the program ROM 104. The program ROM 104 stores a processing program corresponding to a processing procedure described later with reference to FIG. 8, a table for storing required fixed data, and the like. The work RAM 108 is used as a working memory in the course of processing by the CPU 100.

  The ejection recovery process of the recording head 22 includes a suction recovery operation performed with the recording head 22 capped by the cap 50 of the recovery unit 40. In this case, a pump motor 124 serving as a drive source for driving a suction pump 201 described later is driven through the output port 114 and the drive unit 116. In addition, an actuator unit 126 including a recovery valve, which will be described later, is driven.

(Ink system configuration)
FIG. 3 is a schematic diagram for explaining the configuration of each color ink system in the ink jet recording apparatus of the present embodiment. Each color recording head 22 is connected to each color ink tank 28 via a tube 209. The ink tank 28 communicates with the atmosphere, and a negative pressure corresponding to the water head difference between the liquid level of the ink tank and the nozzle position acts on the nozzles of the recording head 22. Due to this negative pressure, a meniscus is formed in the nozzle.

  FIG. 3 shows a state in which the cap 50 is bonded to the recording head 22, and in this state, the ejection surface 22S is substantially sealed. The cap 50 is connected to the suction pump 201 via the connection path 205a, the recovery valve 203, the connection path 205b, the pressure chamber 202, and the connection path 205c. A waste ink tank 204 is provided at the tip of the suction pump 201 and can store the waste ink generated by the suction recovery operation.

  Here, the recovery valve 203 is operable to open and close the connection paths 205a and 205c, that is, to perform connection (opening) / blocking (sealing). Further, the pressure chamber 202 has a predetermined capacity (capacity that is sufficiently larger than the sum of the capacity of the space defined by the cap 50 and the capacity of the connection paths (205a and 205b)). Then, by driving the suction pump 201, it is possible to obtain a depressurized state below the necessary and sufficient atmospheric pressure (accumulate negative pressure). A pressure sensor 206 is attached to the pressure chamber 202 so that the pressure in the pressure chamber 202 can be detected. In the present embodiment, the recovery valve 203, the connection path 205b, the pressure chamber 202, the connection path 205c, and the suction pump 201 are integrally configured to form a suction mechanism. “Negative pressure” means a pressure lower than atmospheric pressure (gauge pressure), and “negative pressure is high (or strong)” means that the absolute pressure is closer to 0 Pa, and “negative pressure is low (or weak). ")" Means closer to gauge pressure.

  FIG. 4 is a perspective view showing the external appearance of the suction mechanism according to the present embodiment configured as an integral block, and FIG. 5 is a diagram of a suction mechanism for illustrating the configuration of the week side of the suction pump 201 for generating suction force. It is a perspective view which fractures | ruptures and shows a part. FIG. 6 is a perspective view in which a part of the suction mechanism is broken to show the configuration of the recovery valve 203 on the week side. FIG. 7A is a diagram showing the surface of the suction mechanism broken along the vertical plane including the one-dot chain line in FIG. 6 from the direction of arrow VIIa, and FIG. 7B is the surface of the suction mechanism broken along the horizontal plane containing the one-dot chain line. It is a figure shown from the arrow VIIb direction.

  As shown in FIG. 5, the suction pump 201 has a form of a tube pump. That is, the suction pump 201 supports the flexible tube 201a, a member 201b formed with a curved surface for holding the flexible tube 201a, a roller 201c capable of pressing the flexible tube 201a toward the curved surface, and the roller. And a rotatable roller support portion 201d. That is, by rotating the roller support portion 201d in the clockwise direction in the drawing, the roller 201c rolls while pressing the flexible tube 201a on the curved surface forming member 201b, and pressurizes the pressure chamber 202. Further, the pressure chamber 202 is decompressed by rotating the roller support portion 201d counterclockwise in the figure. One end side of the tube 201a is connected to one end of a connection path 205c formed inside the suction mechanism, and the other end side of the connection path 205c has a hollow boss shape with an open end, and the tip end portion is a pressure chamber. 202. The other end of the tube 201a is connected to the waste ink tank 204 through a flow path formed inside the suction mechanism.

  As shown in FIG. 6, the recovery valve 203 is disposed in a part of the flow path provided in the pressure chamber 202, is formed of elastic rubber or the like, and is sealed by the actuator unit 126 described above. A stop member 207 is included. The sealing member 207 is attached so as to surround the flow path 208 and the connection path 205 b that form part of the connection path 205 a formed in the pressure chamber 202. Then, by raising the sealing member 207 in the direction of the arrow in FIG. 6, the flow path 208 and the connection path 205b are connected (the recovery valve 203 is opened), while the sealing member 207 is lowered as shown in the figure. The flow path 208 and the connection path 205b are shut off (the recovery valve 203 is sealed).

  As shown in FIGS. 7A and 7B, the flow path 208 has a hole shape extending in the pressure chamber 202, and a ball-shaped sealing member 208 a at the outer wall portion of the pressure chamber 202. On the other hand, it is branched from the middle as a hollow boss shape with an open end. And the front-end | tip part of the boss | hub 208b is connected to the cap 50 through a flexible tube (remaining part of the connection path 205a), for example.

  As described above, in the present embodiment, the recovery valve 203, the pressure chamber 202, and the suction pump 201 are not coupled via a connection member such as a flexible tube, but are integrated as one block. It is configured. For this reason, it becomes possible to stabilize the negative pressure applied to the discharge port in the processing described later without causing deformation (crushing) of the connecting member.

(Recovery processing)
The recovery process according to this embodiment will be described with reference to FIGS.

  FIG. 8 is a flowchart showing a recovery processing procedure of the printer 10 according to the embodiment of the present invention. FIG. 9 is a graph showing the value of the pressure sensor 206 detected when the pressure chamber is depressurized during the suction recovery process. Here, the “normal pressure range” and the “abnormal pressure range” in this figure indicate a state where a required negative pressure for recovery of suction is secured and a state where it is not secured, respectively.

  FIGS. 10A, 10B and 10C are graphs showing values of the pressure sensor 206 detected at the time of ink suction in the recovery process. Here, FIG. 6A shows that the pressure in the pressure chamber 202 increases as desired after the start of ink suction (the negative pressure approaches the atmospheric pressure as desired), so that suction recovery is performed normally. (First case). On the other hand, (b) shows a case (second case) where the pressure in the pressure chamber 202 rises too rapidly (the negative pressure drops too rapidly) after the start of ink suction (after the recovery valve 203 is opened). . (C), conversely, is the case where the pressure rise in the pressure chamber 202 is too slow (the decrease in negative pressure is too slow) (third case). In the first case, the second case, or the third case, the internal pressure of the pressure chamber 202 (that is, the negative pressure acting on the nozzle) after a predetermined time has elapsed since the recovery valve 203 was opened. This can be determined by detection. That is, the detected value is within a predetermined range (normal pressure range), is closer to atmospheric pressure (positive pressure side abnormal pressure range), or is a range where negative pressure is higher than the normal pressure range (negative pressure side pressure). It can be determined based on whether it is in the abnormal range. In determining the first to third cases in this way, instead of performing the determination based on the determination of the range of the pressure value after the elapse of a predetermined time from when the recovery valve 203 is opened, the recovery valve 203 is used. It is also possible to make a determination based on a change in pressure or a change curve after opening.

  Further, FIG. 11 is a graph (pressure detection value) showing a pressure change for explaining processing performed in the present embodiment when the state of FIG. 10C occurs.

  Referring to FIG. 8, when the recovery process is started, the CPU 100 first moves the recording head 22 and the cap 50 relative to each other so that the cap 50 is applied to the ejection surface 22S (step S1). Next, the CPU 100 operates the recovery valve 203 so as to shut off the connection paths 205a and 205c (step S3), and drives the suction pump 201 for a predetermined time to stop it (step S5).

  Next, the CPU 100 reads the detection value (first pressure) of the pressure sensor 206 at the time of the stop, and further reads the detection value (second pressure) of the pressure sensor 206 after a predetermined time has elapsed. The detected values are compared (step S7). Here, if the CPU 100 does not determine that the pressure in the pressure chamber 202 is maintained for a predetermined time by comparing both detection values, the CPU 100 stops the apparatus and issues a notification or a warning to that effect (step S9). ). This is because there is a high possibility that the necessary negative pressure state cannot be maintained due to poor connection or breakage of the connection path or the pressure chamber (the pressure has increased due to the entry of the atmosphere). This avoids the inconvenience of repeating the image formation and confirmation operations without obtaining a sufficient suction recovery effect, and does not cause a decrease in efficiency or waste of ink.

  On the other hand, if the CPU 100 determines that the pressure in the pressure chamber 202 is maintained for a predetermined time, the process proceeds to step S11, and the CPU 100 determines whether or not the pressure value indicates a sufficiently negative pressure state. To do. If the negative pressure state is not sufficient (indicated by the broken line in FIG. 9), the process proceeds to step S13, where the CPU 100 drives the suction pump 201 for a predetermined time and then stops, and the steps S7 and S11 are performed. Repeatedly, the pressure chamber 202 is brought into a sufficiently negative pressure state. If the CPU 100 determines that a sufficient negative pressure state has not been reached at a predetermined number of times (for example, three times), the process can proceed to step S9 to notify or warn. This is because there is a high possibility that the suction pump 201 is extremely deteriorated due to a failure or deterioration of the suction pump 201. This avoids the inconvenience of repeating the image formation and confirmation operations without obtaining a sufficient suction recovery effect, and does not cause a decrease in efficiency or waste of ink.

  In step S11, when the CPU 100 confirms that the pressure chamber 202 is in a sufficiently negative pressure state as indicated by the solid line in FIG. 9, and the steps S7 and S11 are repeated as indicated by the broken line in FIG. If a sufficient negative pressure state is obtained, the process proceeds to step S15. In step S <b> 15, the CPU 100 opens the recovery valve 203 and causes the recording head 22 to perform suction recovery accordingly. By doing so, the pressure in the pressure chamber 202 (that is, the negative pressure acting on the nozzle) increases toward the atmospheric pressure (the negative pressure decreases). Then, after the elapse of a predetermined time s in the process in which the pressure in the pressure chamber 202 increases from the opening of the recovery valve 203, the CPU 100 reads the detection value of the pressure sensor 206 and makes a determination on the value. Here, as shown in FIG. 10A, when the pressure in the pressure chamber 202 is within the normal range after the lapse of the predetermined time s, the CPU 100 continues the suction recovery process as it is, and then the wiping operation (S19). Then, the preliminary discharge operation (step S21) is executed, and this procedure is finished.

  In addition, as shown in FIG. 10B, when the pressure in the pressure chamber 202 after the elapse of the predetermined time s from the opening of the recovery valve 203 is not within the predetermined normal range (when it is within the positive pressure side abnormal pressure range). In step S9, the CPU 100 stops the apparatus and gives a notification or warning. This is because there is a high possibility that the pressure is rising rapidly due to the entry of air into the connection path or pressure chamber. This avoids the inconvenience of repeating the image formation and confirmation operations without obtaining a sufficient suction recovery effect, and does not cause a decrease in efficiency or waste of ink.

  Furthermore, as shown in FIG. 10C, when the pressure in the pressure chamber 202 has not risen to the normal range after the elapse of the predetermined time s from the opening of the recovery valve 203 (in the negative pressure side abnormal pressure range). ), The CPU 100 executes the processes of steps S23 to S29. In such a case, the nozzle is clogged or the like and the resistance to suction is increased. Therefore, the CPU 100 seals the recovery valve 203 (step S23), drives the suction pump 201 for a predetermined time and then stops (step S25), detects the pressure in the pressure chamber 202 in step S27, and obtains a required negative pressure. Is determined. The required negative pressure is a value sufficient to eliminate nozzle clogging, and is set so that the negative pressure in the pressure chamber 202 is higher than that set in step S11 as shown in FIG. be able to. If the required negative pressure is obtained, the CPU 100 opens the recovery valve 203 in step S29 to perform ink suction, and then proceeds to step S19 while the required negative pressure is obtained. If NO is obtained, the process returns to step S25. If the CPU 100 determines that the required negative pressure state has not been reached a predetermined number of times (for example, 3 times) in step S27, the process moves to step S9, and the CPU 100 gives a notification or warning to that effect. This is because there is a high possibility that the pressure rapidly rises due to the entry of the atmosphere into the connection path and the pressure chamber due to the action of the required negative pressure.

(Other embodiments)
In the embodiment described above, as shown in FIG. 10C, when the pressure in the pressure chamber 202 has not risen to the normal range after a predetermined time s has elapsed since the recovery valve 203 was opened, the CPU 100 However, the processes in steps S23 to S29 are executed a predetermined number of times. That is, the CPU 100 shuts off the recovery valve 203 and drives the suction pump 201 for a predetermined time to detect the pressure in the pressure chamber 202 to determine whether a required negative pressure is obtained. 203 is opened (step S29), and ink suction is resumed. However, the processing procedure of FIG. 8 can be changed as follows.

  FIG. 12 is a flowchart showing a modification of the processing procedure of FIG. 8, and the same reference numerals are assigned to steps for performing the same processing as in FIG. In this procedure, if it is determined in step S27 that the required negative pressure state has been reached, the CPU 100 returns to step S15 to open the recovery valve 203, and after a predetermined time has elapsed, A determination process (step S17) is performed. However, in this case, the negative pressure set in the pressure chamber 202 is preferably a required negative pressure (a negative pressure stronger than that set in step S11) sufficient to eliminate nozzle clogging, as in the above example. . Further, the normal pressure range and abnormal pressure range at this time may be different from the normal pressure range and abnormal pressure range set in step S11. Therefore, the CPU 100 determines the pressure (normal pressure range and abnormal pressure range) after the elapse of a predetermined time after the recovery valve 203 is opened with respect to the required negative pressure stored in the pressure chamber 202 in advance, and the CPU 100 determines based on the pressure. Is strongly desirable.

  In the embodiment described above, when the CPU 100 confirms that the required negative pressure is obtained in step S27, the CPU 100 performs pressure determination after a predetermined time has elapsed after opening the recovery valve 203, Is in the normal range or in the negative pressure side abnormal pressure range. In the latter case, wiping and preliminary discharge can be performed to remove as much as possible the factors that can cause clogging of the nozzle, and then the suction process can be performed. Alternatively, or together with this, when it is determined that the suction pressure is in the negative pressure side abnormal range even if the suction process is performed a plurality of times, the nozzle clogging is so strong that it cannot be eliminated. Since there is a high possibility, the apparatus can be stopped and a notification to that effect can be given.

  Further, in the above embodiment, the configuration in which the suction recovery system including the recovery valve 203, the pressure chamber 202, the suction pump 201, and the waste ink tank 204 is provided for one recording head 22 has been described. However, as shown in FIG. 1, in an inkjet recording apparatus using a plurality of recording heads, a common suction recovery system may be provided for two or more recording heads.

  In addition, in the above example, the configuration using the recording heads 22K, 22C, 22M, and 22Y for ejecting inks of K, C, M, and Y has been described. The type of liquid to be discharged can be determined as appropriate.

  In addition, in the above example, the case where the present invention is applied to a so-called line printer type printing apparatus has been described. However, the present invention can also be applied to a so-called serial printer type recording apparatus that performs recording by moving the recording head in a direction intersecting the recording medium conveyance direction and discharging ink in the process.

22, 22K, 22C, 22M, 22Y Recording head 50 Cap 201 Suction pump 202 Pressure chamber 203 Recovery valve 204 Waste ink tank 205a, 205b, 205c Connection path 206 Pressure sensor

Claims (8)

A cap for sealing the surface of the recording head provided with an ejection port for ejecting ink;
A pump connected to the cap to generate a suction force;
A pressure chamber provided in a connection path between the cap and the pump, and decompressed as the pump is driven;
A valve provided in a connection path between the pressure chamber and the cap to open and close the valve;
The pressure chamber is depressurized by driving the pump with the valve closed, and the ink is sucked from the discharge port by opening the valve with the surface sealed by the cap. Control means;
With
The control means determines whether the pressure chamber pressure increase accompanying the opening of the valve is normal in the first case, the second case that is too rapid, or the third case that is too slow, An ink jet recording apparatus characterized in that a warning is given if it is determined to be the second case, while the process is performed again if it is determined that the case is the third case.   The inkjet control apparatus according to claim 1, wherein the control unit performs the determination based on the pressure when a predetermined time has elapsed since the valve was opened.   3. The ink jet recording apparatus according to claim 1, wherein the control unit performs the processing by reducing the pressure chamber more greatly when it is determined that the third case is satisfied. 4. Wiping means for wiping the surface, and preliminary discharge means for performing a preliminary discharge operation for causing the recording head to perform a preliminary discharge operation toward the cap,
The said control means performs the said process after performing the said wiping and the said preliminary discharge operation, when it determines with it being the said 3rd case. Inkjet recording device. The control means seals the valve and drives the pump for a predetermined time and then stops the first pressure in the pressure chamber when the pump is stopped, and after a predetermined time elapses before the valve is opened from the time And the second pressure in the pressure chamber is determined to determine whether the second pressure is maintained at the first pressure,
If this is not done, a warning will be given,
When the maintenance has been performed, it is determined whether or not the pressure chamber is in a sufficiently reduced pressure state for performing the processing. 5. The ink jet recording apparatus according to claim 1, wherein the pump is stopped after being driven for a predetermined time, and the comparison and the determination of the maintenance are performed.   The ink jet recording apparatus according to claim 1, wherein the valve, the pressure chamber, and the pump are integrally configured including a flow path therebetween.   The inkjet recording apparatus according to claim 6, wherein the valve is disposed in a flow path formed in the pressure chamber.   8. The ink jet recording apparatus according to claim 1, wherein the pump has a form of a tube pump.