JP2005225197A - Liquid discharging performance maintenance method and liquid discharging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently maintain the liquid discharging performance by reducing discharge defects of a liquid by a liquid discharging head in a liquid discharging performance maintenance method of a liquid discharging apparatus which discharges the liquid from liquid discharging nozzles of the liquid discharging head. <P>SOLUTION: An ink (predetermined liquid) (i) within a printing head 22 which is supplied from an ink tank 4 to be discharged from the ink discharging nozzle 40a is ejected out of an ink-sending pipe 159, and bubbles mixed in the ink (i) are removed, whereby the discharge defects of the ink (i) are reduced in the liquid discharging performance maintenance method. After the execution of bubble removal through ejection of the ink (i) in the printing head 22 is started, the bubble removal is continuously executed until a fixed time passes since the state that no bubbles are present in the ink (i) ejected from within the printing head 22 is detected. The ink discharge defects of the printing head 2 are thus reduced, and the ink discharging performance maintenance is carried out surely. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for maintaining a liquid discharge performance of a liquid discharge apparatus that discharges liquid from a liquid discharge nozzle of a liquid discharge head, and more specifically, after starting to remove bubbles in the liquid by discharging the liquid in the liquid discharge head Liquid discharge performance that reduces liquid discharge failure and ensures maintenance of liquid discharge performance by continuing to remove the bubbles until a certain time has elapsed after detecting the absence of bubbles in the liquid The present invention relates to a maintenance method and a liquid ejection apparatus that performs the method.

2. Description of the Related Art Conventionally, an apparatus such as an ink jet printer has been widely used as a liquid discharge apparatus that discharges a liquid supplied from a liquid container into a liquid discharge head from a liquid discharge nozzle of the liquid discharge head. When air bubbles are generated in the ink supplied into the print head of such an ink jet printer, the ink may not be ejected from the ink ejection nozzle. In order to prevent such a problem, a technique for discharging bubbles simultaneously by sucking ink from an ink discharge nozzle by bringing an elastic member such as rubber into contact with the nozzle surface of the print head has been conventionally known. ing.
For example, Patent Document 1 uses the above technique to remove air bubbles mixed in ink in the print head at the time of initial filling in which the ink cartridge is attached to the ink jet printer and the print head is filled with ink. An ink jet recording apparatus is disclosed that draws out bubbles simultaneously with ink by sucking ink from ink discharge nozzles.
JP 2000-85153 A

  However, in the technique described in Patent Document 1, the operation of sucking ink from the ink discharge nozzle is performed in a state where a cap member made of an elastic member such as rubber is capped on the nozzle surface of the print head. Therefore, in order to reliably perform the ink suction operation, the cap member must be capped so that there is no leakage with respect to the nozzle surface. Therefore, this technique is applied to a so-called serial type print head ink jet printer, and is difficult to apply to a so-called line type print head ink jet printer. That is, the line type print head ink jet printer has a problem that the elastic member for capping the nozzle surface is also longer than the page width, and it is difficult to cap the nozzle surface without leakage.

  In particular, in a line-type print head in which chips provided with means for ejecting ink from the ink ejection nozzles are alternately mounted on the left and right sides to form a nozzle array, the nozzle array is also not in a straight line, and the wire bond sealing portion is the nozzle surface. Is formed. In such a case, the cap member must be capped on the nozzle surface of the print head in a state avoiding them, and the shape of the cap member becomes complicated, so that there is no leakage to the nozzle surface during capping. Not only is capping difficult, but there is also an adverse effect that the cost of the cap member increases.

  In addition, even if capping without leakage on the nozzle surface of the print head can be realized, with a line type print head having a relatively large number of nozzle rows, ink is sucked from all ink discharge nozzles when ink is sucked after capping. As a result, there is a case where all the nozzles cannot be filled with ink, resulting in a problem that reliability is lacking. Also, even if all the ink discharge nozzles can be filled with the ink by the suction operation, the amount of the suction ink at the time of filling increases, so a large amount of ink containing bubbles must be discarded, and the running cost is reduced. There is also a problem of improving.

  Accordingly, the present invention addresses such a problem, and in a liquid discharge performance maintaining method for a liquid discharge apparatus that discharges liquid from a liquid discharge nozzle of a liquid discharge head, the liquid in the liquid discharged from the liquid discharge head is discharged. After the start of the bubble removal, the bubble removal is reduced and the liquid discharge performance is reduced by continuing the bubble removal until a certain time has elapsed after detecting the absence of bubbles in the liquid. It is an object of the present invention to provide a liquid discharge performance maintaining method for reliably maintaining a liquid discharge apparatus for performing the method.

  In order to achieve the above object, a liquid discharge performance maintaining method according to the present invention is a liquid discharge head that discharges liquid supplied from a liquid container containing a predetermined liquid from a liquid discharge nozzle formed on a nozzle surface. Is a liquid discharge performance maintaining method for reducing defective discharge of liquid by removing bubbles mixed in the liquid, wherein the liquid is discharged from the liquid discharge head to remove bubbles in the liquid. After the start of the bubble removal, the bubble removal is continued until a certain period of time elapses after detecting the absence of bubbles in the liquid discharged from the liquid discharge head.

  By carrying out such a method, after the bubble removal is started, the bubble removal is continued until a certain time elapses after detecting the absence of bubbles in the liquid discharged from the liquid discharge head. .

  In another liquid discharge performance maintaining method according to the present invention, the liquid supplied from a liquid container that stores a predetermined liquid is discharged from the liquid discharge head that discharges from the liquid discharge nozzle formed on the nozzle surface, A liquid discharge performance maintaining method for reducing defective liquid discharge by removing bubbles mixed in the liquid, wherein the liquid is discharged from the liquid discharge head to remove bubbles in the liquid. After the start of the bubble removal, the liquid discharged from the liquid discharge head is detected until there is no bubble in the liquid until at least the volume of liquid contained in the liquid discharge head has been discharged. Continue to remove bubbles.

  By implementing such a method, after detecting that there is no bubble in the liquid discharged from the liquid discharge head after starting the bubble removal, at least the volume of liquid stored in the liquid discharge head The bubble removal operation is continued until the discharge is completed.

  In addition, a liquid discharge apparatus according to the present invention includes a liquid container that stores a predetermined liquid, a liquid discharge head that is supplied with the liquid stored in the liquid container and discharges the liquid from a liquid discharge nozzle formed on a nozzle surface. A liquid delivery pipe connected to a liquid discharge port for discharging the liquid in the liquid discharge head and serving as a discharge flow path for the liquid, and a suction disposed on the liquid delivery pipe for sucking the liquid in the liquid discharge head A detecting means for detecting the state of the liquid in the liquid delivery pipe, and the liquid delivery apparatus comprising: a detecting means for detecting the state of the liquid in the liquid delivery pipe; Control means for controlling the operation of the suction means, and measuring means for measuring the time for stopping the operation of the suction means and sending a control signal to the control means.

  With such a configuration, the state of the liquid in the liquid delivery pipe from which the liquid in the liquid discharge head is discharged is detected by the detection unit, and the control unit operates the suction unit based on the state of the liquid detected by the detection unit. Is controlled, the liquid is sucked and discharged from the liquid discharge head, and bubbles in the liquid are removed. In this state, the time for stopping the operation of the suction means is measured by the measurement means, and the bubble removal is continued until a predetermined time elapses.

  According to the liquid ejection performance maintaining method according to claim 1, since the bubble removal is continuously performed until a predetermined time has elapsed since the absence of bubbles in the liquid ejected from the liquid ejection head is detected, the liquid ejection The liquid discharge performance can be reliably maintained to reduce defects. Therefore, it becomes possible to control the liquid discharged from the liquid discharge head to an appropriate amount, and the amount of liquid waste liquid can be minimized.

  According to the liquid ejection performance maintaining method according to claim 2, at least a volume of liquid that can be accommodated in the liquid ejection head after detecting the absence of bubbles in the liquid ejected from the liquid ejection head. Since the bubble removal is continued until the liquid is completely discharged, the liquid discharge performance can be reliably maintained to reduce the liquid discharge failure. Therefore, the liquid discharged from the liquid discharge head can be controlled to an appropriate amount, and the amount of liquid waste can be minimized.

  Further, according to the liquid ejection device of the third aspect, the operation of the suction unit is controlled by the control unit based on the state of the liquid in the liquid delivery pipe from which the liquid in the liquid ejection head is discharged, and from the inside of the liquid ejection head. The liquid is aspirated and discharged, and bubbles in the liquid are removed. After starting the bubble removal, the measurement means measures the time for stopping the operation of the suction means and continues the bubble removal until a predetermined time elapses. Done. In addition, it is possible to appropriately remove bubbles in the liquid in the liquid discharge head, and the reliability of the liquid discharge performance can be greatly improved. At this time, even if the liquid containing the gas is not sucked from the liquid discharge nozzle, the liquid in the liquid discharge head can be discharged and the bubbles can be removed, so a means for sucking the liquid from the liquid discharge nozzle is provided. It does not have to be provided in the head cap. Therefore, the mechanism for carrying out the bubble removal has a simple configuration, and the entire apparatus does not increase in size.

  Here, according to the invention according to claim 4, the detection means is an optical sensor that optically detects the presence or absence of bubbles in the liquid flowing in the liquid delivery tube, so that the optical sensor can detect the presence of bubbles in the liquid delivery tube. The state of the liquid can be detected.

  Further, according to the invention of claim 5, the detection means is a pressure sensor that detects the presence or absence of bubbles in the liquid flowing in the liquid delivery pipe by a pressure change. The state of the liquid can be detected.

  Further, according to the invention according to claim 6, the liquid reflux line is configured to connect the liquid discharge port of the liquid delivery pipe to the liquid container and return the liquid discharged from the liquid discharge head to the liquid container. As a result, the liquid discharged to remove the bubbles of the liquid in the liquid discharge head is returned to the liquid container. Accordingly, it is possible to economically remove bubbles in the liquid in the liquid discharge head.

  According to the seventh aspect of the present invention, the detection means is disposed immediately after the liquid discharge port of the liquid discharge head, thereby shortening bubbles in the liquid discharged from the liquid discharge head. Can be detected in time. Therefore, it is possible to efficiently remove bubbles in the liquid in the liquid discharge head.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory view showing an embodiment of a liquid ejection performance maintaining method according to the present invention. In this method for maintaining liquid ejection performance, ink (predetermined liquid) i supplied from an ink tank (liquid container) 4 mounted on an ink jet printer as a liquid ejection device is used as a nozzle surface 40 of a print head (liquid ejection head) 22. The ink discharge nozzle (liquid discharge nozzle) 40a formed on the ink discharge nozzle (40a) reduces the ink discharge failure and maintains the liquid discharge performance. The gas is discharged from the tube (liquid delivery tube) 159 and the bubbles mixed in the ink i are removed.

  Here, in the liquid ejection performance maintaining method according to the present invention, the ink i in the print head 22 is discharged from the ink delivery tube 159 to remove bubbles in the ink i, and after the bubble removal is started, The bubble removal is continuously performed until a predetermined time has elapsed after the bubble sensor 202 detects the absence of bubbles in the ink i discharged from the print head 22. As a result, the liquid discharge performance can be reliably maintained to reduce ink discharge defects caused by the ink discharge nozzles 40a of the print head 22. Therefore, it becomes possible to control the liquid discharged from the liquid discharge head to an appropriate amount, and the amount of waste liquid of the ink i can be suppressed to the minimum.

  Further, according to another method for maintaining the liquid ejection performance according to the present invention, after the ink i in the print head 22 is discharged from the ink delivery tube 159, the bubbles in the ink i are removed and the bubble removal is started. The air bubble sensor 202 detects that there is no air bubble in the ink i discharged from the print head 22, and at least until the volume of the ink i accommodated in the print head 22 has been discharged. Continue to carry out the removal. As a result, the liquid discharge performance can be reliably maintained to reduce ink discharge defects caused by the ink discharge nozzles 40a of the print head 22. Therefore, it becomes possible to control the liquid discharged from the liquid discharge head to an appropriate amount, and the amount of waste liquid of the ink i can be suppressed to the minimum.

  Next, an ink jet printer as a liquid ejecting apparatus used directly for implementing the liquid ejecting performance maintaining method according to the present invention will be described. This ink jet printer supplies ink i from the ink tank 4 into the print head 22 and discharges the ink i from an ink discharge nozzle 40a formed on the nozzle surface 40. The ink tank 4 and the ink supply The unit 21, the print head 22, the ink delivery pipe 159, and the electric pump 201 are provided, and the bubble sensor 202, the control unit 204, and the timer 207 are further provided.

  The ink tank 4 shown in FIG. 1 is a liquid container that contains ink, and is formed by, for example, injection molding a resin material or the like, and is formed in a box shape. An ink supply unit 21 is attached to the center of the bottom surface of the ink tank 4. The ink supply unit 21 serves as a flow path for supplying ink i accommodated in the ink tank 4 to a print head 22 to be described later, and an ink adjustment valve 29 is provided in the middle thereof. The ink adjustment valve 29 serves as means for adjusting the flow rate of the ink i that has flowed from the ink tank 4 through the ink supply unit 21, and the ink i supplied into the print head 22, which will be described later. This prevents natural leakage from the ink discharge nozzle 40a.

  A print head 22 is provided at the lower end of the ink supply unit 21. This print head 22 is called a line-type print head in which a large number of ink discharge nozzles 40a are arranged in the longitudinal direction of a thin plate-like nozzle member 40 that constitutes the nozzle surface. An ink flow path 42 serving as a liquid chamber is configured, and the ink i supplied into the ink flow path 42 is discharged from the ink discharge nozzle 40a. At both ends of the upper surface of the print head 22, there are provided deaeration ports 51 for discharging the ink i accommodated in the ink flow path 42 and performing deaeration.

  In addition, an ink delivery pipe 159 is connected to these deaeration ports 51. The ink delivery tube 159 serves as a discharge passage for delivering the ink i in the print head 22, and is made of, for example, a flexible resin tube or a metal pipe such as stainless steel.

  Further, an electric pump 201 is disposed in the middle of the ink delivery pipe 159. The electric pump 201 serves as a suction unit that sucks the ink i in the print head 22, and includes, for example, a tube pump, a diaphragm pump, a piston pump, or the like, and an appropriate one may be selected according to specifications. The ink i in the ink flow path 42 of the print head 22 sucked and discharged by the electric pump 201 flows out from the waste liquid port 159 a at the end of the ink delivery pipe 159 and is discarded in the waste ink tank 152. It has become. Thus, the ink i in the print head 22 is sucked and discharged by the electric pump 201, and bubbles mixed in the ink i are removed.

  Here, in the present invention, the bubble sensor 202 is disposed on the ink delivery tube 159. The bubble sensor 202 serves as detection means for detecting the state of the ink i in the ink delivery tube 159. As shown in FIG. 2, the light sensor 202b receives light emitted from the light emitting unit 202a, The difference in transmittance due to the presence or absence of bubbles in the ink i flowing through the ink delivery tube 159 is optically detected. In this case, at least a portion of the ink delivery pipe 159 where the bubble sensor 202 is disposed is made of a transparent color material that transmits light from the bubble sensor 202. Thereby, the bubble sensor 202 can detect the state of the ink i in the ink delivery tube 159, that is, the presence or absence of bubbles in the ink i.

  At this time, when the bubble sensor 202 is used, regardless of the type, unless the measurement environment between the light emitting unit 202a and the light receiving unit 202b is stabilized, an error occurs in the transmission and reflection characteristics, and it cannot be accurately detected. In this example, as shown in FIG. 2 (b), the ink delivery tube 159 that passes through the bubble sensor 202 is shaped to have a substantially parallel surface, and the space between the parallel surfaces is measured so that the inside thereof is measured. It is easy to sense the state of the bubble of the ink i that passes through, and a stable detection result can be obtained.

  FIG. 3 is a view showing another embodiment for making the ink delivery tube 159 into a substantially parallel surface shape. In this embodiment, a plurality of ribs 206 are provided on the holding member 205 that holds the ink delivery tube 159, and a portion of the ink delivery tube 159 made of a soft material through which the light of the bubble sensor 202 passes is sandwiched between the ribs 206. And deformed to form a substantially parallel surface. Even in this case, the same effect as described above can be obtained.

  As shown in FIG. 1, a control unit 204 is connected to the electric pump 201 and the bubble sensor 202. The control unit 204 serves as a control unit that controls the operation of the electric pump 201 based on the state of the ink i detected by the bubble sensor 202. The control unit 204 determines the state of the ink i detected by the bubble sensor 202. A signal is input and a control signal for controlling the operation of the electric pump 201 is output. Accordingly, based on the state of the ink i in the ink delivery pipe 159 detected by the bubble sensor 202, the electric pump 201 is operated to discharge the ink i from the print head 22, and the bubbles in the ink i are removed. Since it can be removed, ink discharge failure of the ink discharge nozzle 40a can be reduced and ink discharge performance can be efficiently maintained.

  A timer 207 is connected to the control unit 204. The timer 207 serves as a measuring unit that measures the time of the operation stop of the electric pump 201 and sends a control signal to the control unit 204. The timer 207 is configured to measure the volume of the ink flow path 42 of the print head 22 and the electric pump 201. The measurement time can be set arbitrarily according to the specifications. Accordingly, the operation of the electric pump 201 is controlled by the control unit 204, and the ink i is sucked and discharged from the print head 22, and bubbles in the ink i are removed. After the start of the bubble removal, the bubble sensor 202 detects the absence of bubbles in the ink i in the ink delivery tube 159, and then the timer 207 measures the operation stop time of the electric pump 201. Then, the bubble removal of the ink i is continued until an arbitrarily set predetermined time elapses. Such bubble removal is performed because there are cases where bubbles are intermittently present in the ink flow path 42 of the print head 22, even if the bubble sensor 202 detects the absence of bubbles in the ink i. This is to prevent air bubbles immediately after that, and as a result, cause a printing defect equivalent to false detection.

  Accordingly, since the bubble removal is surely performed, it is possible to reliably maintain the liquid ejection performance that reduces ink ejection failure. In addition, it is possible to appropriately remove bubbles in the liquid in the liquid discharge head, and the reliability of the liquid discharge performance can be greatly improved. At this time, even if the liquid containing the gas is not sucked from the liquid discharge nozzle, the liquid in the liquid discharge head can be discharged and the bubbles can be removed, so a means for sucking the liquid from the liquid discharge nozzle is provided. It does not have to be provided in the head cap. Therefore, the mechanism for carrying out the bubble removal has a simple configuration, and the entire apparatus does not increase in size.

  In addition, the bubble removal of the ink i described above is carried out by detecting the state where there is no bubble in the ink i discharged from the print head 22 with the bubble sensor 202 and at least the volume integrated in the print head 22. It may be continued until the ink i is completely discharged. For example, it is assumed that the volume of ink i that can be accommodated in the print head 22 is 0.46 cc, and the suction capability of the electric pump 201 is 6 cc / min. In this case, it takes about 4.6 seconds until the electric pump 201 finishes discharging all the ink i stored in the print head 22. Accordingly, after the bubble sensor 202 detects the absence of bubbles in the ink i, the operation of the electric pump 201 may be continued until the time of about 4.6 seconds elapses as described above. As a result, at least the volume of the ink i accommodated in the print head 22 can be discharged, so that the bubbles in the ink i can be removed efficiently and accurately. Therefore, it is possible to efficiently maintain the liquid ejection performance that reduces ink ejection defects.

  Further, since the ink i discharged from the print head 22 can be controlled to an appropriate amount based on the state of the ink i detected by the bubble sensor 202, the amount of waste ink i can be minimized. Furthermore, the bubbles in the ink i in the print head 22 can be appropriately removed, and the reliability of the ink ejection performance can be greatly improved. At this time, unlike the prior art described in Patent Document 1, the ink i in the print head 22 is discharged to remove bubbles without sucking the ink i containing gas from the ink discharge nozzle 40a. Therefore, it is not necessary to provide a means for sucking the ink i from the ink discharge nozzle 40a in the head cap. Therefore, the mechanism for carrying out the bubble removal can be configured in a simple manner so that the entire apparatus is not increased in size.

  Further, by disposing the bubble sensor 202 immediately after the deaeration port 51 of the print head 22, it is possible to detect bubbles in the ink i discharged from the print head 22 in a short time. Accordingly, it is possible to efficiently remove the bubbles in the ink i.

  FIG. 4 is an explanatory view showing a second embodiment of the ink jet printer according to the present invention. In this embodiment, a drain outlet 159 b at the end of the ink delivery pipe 159 is connected to the bottom surface of the ink tank 4, and an ink return pipe that circulates the ink i in the print head 22 and returns it to the ink tank 4 is provided. It is composed. In this example, the deaeration port 51 of the print head 22 and the ink tank 4 are connected by an ink delivery pipe 159 that forms a circulation flow path, and the ink i can be circulated by the electric pump 201. As a result, the ink i discharged from the print head 22 in order to remove bubbles is returned to the ink tank 4, so that the ink i can be used efficiently, and the bubbles in the ink i can be removed economically. Can be implemented.

  At this time, the defoaming filter 203 is arranged in the ink reflux pipe, and the ink i that has flowed out of the deaeration port 51 of the print head 22 passes through the bubble sensor 202, the electric pump 201, and the defoaming filter 203 to the ink tank 4. To come back. As in the case shown in FIG. 1, the electric pump 201 and the bubble sensor 202 are electrically connected by the control unit 204, and the operation of the electric pump 201 can be controlled by information from the bubble sensor 202. Therefore, as the air bubble sensor 202 is installed near the deaeration port 51 of the print head 22 as in this example, there is an advantage that the time for circulating the ink i can be saved. The defoaming filter 203 incorporates a filtering material, and positively separates the ink i and bubbles to increase the efficiency of deaeration. Further, by providing the bubble sensor 202 immediately after the deaeration port 51 of the print head 22, the bubbles in the ink i discharged from the print head 22 can be detected in a short time, and the bubbles in the ink i are detected. Removal can be performed efficiently.

  In the above description, the optical bubble sensor 202 is provided as a detecting means for detecting the state of the ink i in the ink delivery tube 159. However, the present invention is not limited to this, Detection means may be used. For example, a pressure sensor that detects the presence or absence of bubbles in the ink flowing through the ink delivery tube 159 by pressure change may be used. Also in this case, since the state of the ink i in the ink delivery tube 159 can be detected by the pressure sensor, the same effect as described above can be obtained.

Next, the operation of the liquid discharge performance maintaining method of the printer apparatus configured as described above will be described with reference to the flowchart shown in FIG. First, in the initial state of the operation for maintaining the liquid ejection performance, it is determined whether or not the ink tank 4 is correctly attached to the ink supply unit 21 shown in FIG. 1 (step S1). When the ink tank 4 is not correctly installed, the step S1 proceeds to “No” and the warning display 1 is displayed on the display panel 110 of the printer main body 3 shown in FIG. 6 (step S2). It can be confirmed whether or not it is correctly attached.
If the ink tank 4 is correctly installed, step S1 proceeds to “Yes”, and the amount of ink in the ink tank 4 is determined (step S3). When the amount of ink is smaller than the reference value, step S3 proceeds to “No”, and the warning display 2 is displayed on the display panel 110 (step S4). In this case, the ink tank 4 may be replaced with a new one.
If it is determined in step S3 that the amount of ink in the ink tank 4 is equal to or greater than the reference value, the process proceeds to “Yes”, and a degassing start notice is displayed on the display panel 110 (step S5). The electric pump 201 shown in FIG. 1 or 4 is operated (step S6). As a result, the ink i is discharged from the print head 22 and the bubbles in the ink i are removed, so that the ink discharge failure is reduced and the ink discharge performance is maintained. At this time, in step S7, if the bubble sensor 202 continues to detect the state of the ink in the ink delivery tube 159 and the amount of bubbles in the ink is greater than the reference value, step S7 proceeds to the “No” side. Return to step S6. Thereby, the implementation of the ink ejection performance is continued through steps S6 and S7.

  In step S7, when the bubble sensor 202 detects that the amount of bubbles in the ink in the ink delivery tube 159 has become equal to or less than the reference value, specifically, the ink discharged from the print head 22 When it is detected that there is almost no bubbles in i, the process proceeds to “Yes”, the timer 207 is activated (step S8), and the time for stopping the operation of the electric pump 201 is measured. In step S9, step S9 proceeds to “No” until the predetermined time set arbitrarily, and the bubble removal in the ink i is continued. As a result, since the bubble removal is continued until a certain period of time elapses after the absence of bubbles in the ink i discharged from the print head 22 is detected, the liquid discharge performance can be maintained to reduce ink discharge defects. Surely done. When the set time has elapsed, step S9 proceeds to the “Yes” side, the operation of the electric pump 201 is stopped (step S10), and the deaeration completion is displayed on the display panel 110 (step S11). ). At this time, in step S12, the bubble sensor 202 detects the amount of ink i in the ink delivery tube 159. When the ink amount is larger than the reference value, the warning display 2 is displayed on the display panel 110 as described above (step S13). When the ink amount is below the reference value, the operation for maintaining the liquid ejection performance is finished. To do.

  FIG. 6 is a perspective view showing an ink jet type printer apparatus to which the present invention is applied. The printer device 1 prints an image or characters composed of dots by landing while ejecting liquid ink on a recording paper to be printed. An ink discharge port for discharging ink Is a device having a so-called line-type print head in which a plurality of nozzles are arranged in a substantially straight line with a length corresponding to the width of the recording paper.

The printer apparatus 1 includes a print head cartridge (hereinafter referred to as a head cartridge) 2 to which the present invention is applied, and a printer main body 3 that is an apparatus main body to which the head cartridge 2 is mounted.
As shown in FIGS. 6 and 7, the head cartridge 2 includes a cartridge main body 5 in which an ink tank 4 for containing ink is mounted. The cartridge main body 5 includes yellow, cyan, Ink tanks 4y, 4m, 4c and 4k consisting of four colors of magenta and black are detachable.

  These four ink tanks 4y, 4m, 4c, and 4k are containers formed in a substantially rectangular parallelepiped shape by, for example, injection molding of a resin material or the like, and contain ink corresponding to each color inside. . In addition, these four ink tanks 4y, 4m, 4c, and 4k have an inner surface that is in contact with ink with a surface roughness that is more rough than an outer surface so that minute foreign matters such as dust can be easily removed when the inside is cleaned. Is getting smaller. The four ink tanks 4y, 4m, 4c, and 4k have a long shape corresponding to the longitudinal direction of the cartridge body 5 in order to accommodate as much ink as possible. The ink tanks 4y, 4m, 4c and 4k are arranged side by side in the short side direction of the cartridge body 5.

  The four ink tanks 4y, 4m, 4c, and 4k have a capacity larger than that of the other ink tanks 4y, 4m, and 4c, and the thickness of the black ink tank 4k that consumes the largest amount of ink. It has the same structure except having. Therefore, the configuration of the ink tanks 4y, 4m, 4c, and 4k will be collectively described as the ink tank 4 below.

  As shown in FIGS. 1 and 7, the ink tank 4 includes an ink storage unit 6 that is a liquid storage unit that stores the ink i, and ink that sends the ink i in the ink storage unit 6 to the ink supply unit 21. It has a delivery part 7, an external communication hole 8 for allowing the ink storage part 6 to communicate with the outside, and an air introduction tube 9 for introducing external air into the ink storage part 6 from the external communication hole 8. The ink storage portion 6 forms a storage space for storing the ink i, and has an inner shape substantially corresponding to the outer shape of the ink tank 4 in order to store as much ink i as possible. The ink delivery unit 7 is a rubber member that communicates with the ink storage unit 6, and is provided so as to protrude downward from the center of the lower surface of the ink storage unit 6.

  As shown in FIG. 1, the external communication hole 8 is provided at the center of the upper surface of the ink containing portion 6. Further, the external communication hole 8 is closed by a sealing member (not shown) having air permeability. Thereby, in the ink tank 4, the ink i is prevented from leaking outside from the external communication hole 8, and dust or the like is generated in the ink storage portion 6 when external air is taken in from the external communication hole 8. Preventing intrusion. The air introduction tube 9 is provided so as to extend downward from the external communication hole 8 into the ink containing portion 6. Thereby, in the ink tank 4, when the ink i in the ink containing portion 6 is sent out from the ink sending portion 7 to the cartridge main body 5, the air corresponding to the amount of decrease in the ink i in the ink containing portion 6. Is taken into the ink containing portion 6 from the external communication hole 8 through the air introduction tube 9.

  Further, in the middle portion of the air introduction tube 9, a liquid storage portion that temporarily stores the ink i so that the ink i that flows backward from the ink storage portion 6 does not suddenly flow out of the external communication hole 8. An ink reservoir 11 is provided. The ink storage portion 11 forms a substantially rhombus-shaped internal space in which the longer diagonal line when viewed from the front is aligned with the longitudinal direction of the ink storage portion 6, and the upper corner portion defines the air introduction tube 9. In addition to communication with the external communication hole 8, the lower corner portion is in communication with the ink containing portion 6 through the air introduction tube 9. Thus, in the ink tank 4, the ink storage unit 11 temporarily stores the ink i that has flowed back from the ink storage unit 6 through the air introduction tube 9, so that the ink i does not leak to the outside from the external communication hole 8. The ink i can be returned again to the ink container 6 side.

  Further, as shown in FIG. 7, the cartridge body 5 to which the ink tank 4 as described above is attached is connected to the ink delivery part 7 of the ink tank 4 described above, and connected to the connection part 20. An ink supply unit 21 (see FIG. 1) that is a liquid supply unit that supplies ink i from the ink tank 4 and a print head 22 that discharges the ink i supplied by the ink supply unit 21. ing.

  The connecting portion 20 is a nozzle provided at the center of the bottom surface of the tank mounting portion 14, and its tip is fitted into the ink delivery port 7 a of the ink delivery portion 7 described above, whereby the ink delivery portion of the ink tank 4. 7 is connected. The connecting portion 20 is provided with a sealing member such as an O-ring to prevent the ink i from leaking from the connected ink delivery portion 7. An ink supply unit 21 is provided below the connecting unit 20.

  Further, as shown in FIGS. 6 and 7, a head cap 49 that protects the nozzle surface 40 and prevents the nozzle surface 40 from drying is provided on the bottom surface of the cartridge body 5. The head cap 49 is a substantially rectangular tray, and is opened / closed by a cap opening / closing mechanism 108 of the printer body 3 to be described later, and forms a bottom surface continuous with the cartridge body 5 when closed. The head cap 49 is rotatably attached with a cleaning roller 50 that removes excess ink i attached to the nozzle surface 40 while being in contact with the nozzle surface 40 in accordance with the opening / closing operation.

  As shown in FIG. 6, the printer main body 3 to which the head cartridge 2 configured as described above is mounted includes an upper casing 100a and a lower casing 100b in order to prevent dust and the like from entering the inside. The outer casing 100 has a structure assembled inside. The upper housing 100a is provided with a head mounting portion 101 to which the above-described head cartridge 2 is mounted. The head mounting unit 101 includes an opening 102 corresponding to the head cartridge 2, a holding frame 103 that holds the outer periphery of the head cartridge 2 so as to surround the opening 102, and the holding frame 103. And a head fixing mechanism 104 for fixing the outer peripheral portion.

  The head fixing mechanism 104 includes three knobs 105 provided at the front-side center and the rear-side both ends of the outer periphery of the head cartridge 2, and the three knobs 105 correspond to the three knobs 105. Of the holding frame 103 of the mounting portion 101, it has three holes 106 provided at the front-side center and the back-side both ends, and the holding frame 103 of the head mounting portion 101 has an outer peripheral portion of the head cartridge 2. In the state where the knob is in contact, the tip of each knob 105 is inserted into the hole 106, and the hook provided at the tip of the knob 105 is a spring provided in the hole 106 while twisting the knob 105. By engaging with the head cartridge 2, the head cartridge 2 is fixed to the printer main body 3.

  Further, when the head cartridge 2 is mounted on the head mounting portion 101, the nozzle surface 40 located below the head cartridge 2 faces a printing position in the lower housing 100b described later. Further, as shown in FIG. 7, the head cartridge 2 is provided with a handle portion 107 for removal from the head mounting portion 101 of the printer main body 3 so that the head cartridge 2 can be easily removed when the head cartridge 2 is replaced. It has become.

  The upper casing 100a is provided with a cap opening / closing mechanism 108 for opening / closing the head cap 49 of the head cartridge 2. The cap opening / closing mechanism 108 moves the head cap 49 to the front side and opens the nozzle surface 40 of the head cartridge 2 during the printing shown in FIG. 10, while the printing is completed as shown in FIG. Further, the head cap 49 is moved to the back side by the operation opposite to the above-described operation, and the nozzle surface 40 of the head cartridge 2 is closed.

  Further, as shown in FIG. 6, a lid body 100c that closes the opening 102 of the head mounting portion 101 is attached to the upper housing 100a so as to be opened and closed. The lid 100c can close the opening 102 of the head mounting portion 101 in a state where the head cartridge 2 is mounted on the head mounting portion 101, and closes the opening 102 of the head mounting portion 101. At this time, an upper surface portion continuous with the upper housing 100a is formed. Further, operation buttons 109a and 109b for performing various operations, a printing state, and the like are displayed on the upper surface portion of the upper casing 100a, which is located on the front side where a recording sheet P to be described later is supplied and discharged. A display panel 110 and the like are provided.

Further, as shown in FIG. 9, the front side of the outer casing 100 is configured such that the upper casing 100a is supported by the lower casing by both side surfaces of the upper casing 100a being pivotally supported by a frame (not shown) in the lower casing 100b. It can be opened and closed with respect to 100b.
Further, as shown in FIGS. 6 and 8, a paper supply / discharge port 111 through which the recording paper P is supplied / discharged is provided on the front surface of the outer casing 100. The storage tray 112 that stores the recording paper P is attached to the paper supply / discharge port 111 to enable paper feeding. The recording paper P passes through the paper supply / discharge port 111 and is out of the open end of the storage tray 112. The paper is discharged onto the lid tray 113 that closes the front side.

  On the other hand, inside the lower housing 100b, as shown in FIGS. 8 and 10, a paper feeding unit 114 that feeds the recording paper P from the storage tray 112, and the recording paper fed by the paper feeding unit 114 A transport unit 115 that transports P to the printing position and a paper discharge unit 116 that discharges the recording paper P transported by the transport unit 115 are provided, which are not shown in the lower casing 100b. It is assembled to the frame.

  The paper feed unit 114 is a paper feed roller 117 that feeds the recording paper P in the storage tray 112 to the transport unit 115 as a paper feed unit for feeding the recording paper P from the storage tray 112 to the transport unit 115. A pair of separation rollers 118a and 118b for feeding the recording paper P fed from the paper feed roller 117 to the transport unit 115 one by one are provided, and these are driving units provided in the lower casing 100b. While being interlocked with each other by a mechanism (not shown), it is rotationally driven in the directions of arrows A1, A2, and A3 in FIG.

  The paper feed roller 117 is disposed above the recording paper P facing the opening end on the back side of the storage tray 112, and the outer peripheral surface thereof is a paper push-up mechanism (not shown) provided in the storage tray 112. ) Can be brought into contact with the recording paper P pushed up. The pair of separation rollers 118a and 118b are positioned in the vicinity of the back side of the paper feed roller 117, and are rotationally driven in the same direction while sandwiching the recording paper P fed by the paper feed roller 117 therebetween. As a result, even when the paper feed roller 117 mistakenly feeds two sheets of recording paper P at the same time, one separation roller 118a feeds one sheet of recording paper P in contact with the outer peripheral surface to the back side, When the separation roller 118b sends back another recording sheet P in contact with the outer peripheral surface thereof to the storage tray 112 on the front side, only one sheet can be sent to the reversing roller 119 side.

The transport unit 115 serves as a transport unit for transporting the recording paper P from the paper feeding unit 114 to the paper discharge unit 116, and a reverse roller 119 that reverses the feeding direction of the recording paper P and the reverse roller 119. A conveyance belt 120 that conveys the recording paper P to the printing position is provided.
The reversing roller 119 is disposed on the back side in the housing 100 and is rotationally driven in the direction of arrow B in FIG. 10 by a drive mechanism (not shown) provided in the lower housing 100b. Further, on the back side of the reversing roller 119, a plurality of pressing rollers 121 a, 121 b, 121 c that press the recording paper P reversed along the outer circumferential surface of the reversing roller 119, and the outer circumferential surface of the reversing roller 119 are opposed. And a curved regulating plate 122 that regulates the movement of the recording paper P.

  In addition, a guide plate 123 for guiding the recording paper P is provided between the reversing roller 119 and the pair of separation rollers 118a and 118b on the lower housing 100b side. Further, between the reversing roller 119 and the conveying belt 120, a guide plate 124 that guides the recording paper P, and a flat regulation plate 125 that faces the guide plate 124 and restricts the movement of the recording paper P, Is provided on the upper housing 100a side.

  The conveyor belt 120 is an endless drive belt wound between a drive pulley 126a and a driven pulley 126b, and the drive pulley 126a is rotationally driven by a drive mechanism (not shown) provided in the lower housing 100b. As a result, it is rotationally driven in the direction of arrow C in FIG. Thereby, the recording paper P can be conveyed to the front side. Further, the transport belt 120 is retracted by a lifting mechanism (not shown) provided in the lower housing 100b and at a transport position where the transport operation is performed at the time of printing shown in FIG. 10 and when it is not driven as shown in FIG. It can be moved up and down between the retreat position. Thereby, the transport belt 120 can prevent a collision with the head cap 49 moved by the cap opening / closing mechanism 108 when the head cartridge 2 is mounted on the head mounting portion 101 described above.

  Further, the transport belt 120 is provided with a platen plate 127 that makes the recording paper P transported to the printing position face the nozzle surface 40 of the head cartridge 2. Further, the transport belt 120 is pushed down by an amount corresponding to the thickness of the platen plate 127 by a pair of pinch rollers 128a and 128b at the front and rear of the platen plate 127. Further, the platen plate 127 is disposed in parallel with the nozzle surface 40 of the head carriage 2 described above at a printing position shown in FIG. The paper discharge unit 116 has a spur 129 disposed as opposed to the driven pulley 126 b via the transport belt 120 as a paper discharge unit for discharging the recording paper P transported by the transport unit 115. The recording paper P is sent out from between the belt and the conveyor belt 120 toward the paper supply / discharge port 111 side.

  In the printer apparatus 1 configured as described above, when the printing operation is started, first, the cap opening / closing mechanism 108 moves the head cap 49 to the front side, and the nozzle surface 40 of the head cartridge 2 is opened. The transport belt 120 is moved up and down from the retracted position to the transport position by the lifting mechanism.

  Next, when the recording paper P stored in the storage tray 112 is pushed up by the paper lifting mechanism, the recording paper P pressed against the outer peripheral surface of the paper feeding roller 117 rotating in the direction of arrow A1 in FIG. Is done. Then, the fed recording paper P is sent out to the back side indicated by an arrow X1 in FIG. 10 while passing between a pair of separation rollers 118a and 118b rotating in the directions of arrows A2 and A3 in FIG.

  Next, the recording paper P sent out to the back side is reversed along the outer peripheral surface of the reversing roller 119 while moving on the guide plate 123, and this time, it is sent out to the front side shown by the arrow X2 in FIG. . The recording paper P sent to the front side is conveyed to the printing position by the conveying belt 120 rotating in the direction of arrow C in FIG. 10 while passing between the guide plate 124 and the regulating plate 125.

  Next, at the printing position, the platen plate 127 is arranged in parallel with the nozzle surface 40 of the head carriage 2 and facing the nozzle surface 40 with a predetermined distance, and the recording paper P pushed up by the platen plate 127 is the nozzle surface 40 of the head carriage 2. Will be opposed to each other. Then, the head cartridge 2 ejects ink i onto the recording paper P conveyed to the printing position, and landes to record an image, characters, and the like composed of dots.

  Next, the recording paper P for which printing has been completed is sent out from between the conveyor belt 120 and the spur 129 to the back side indicated by the arrow X2 in the figure by driving the conveyor belt 120, and from the paper supply / discharge port 111. The paper is discharged onto the lid tray 113.

  Finally, when the printing operation is completed, the conveying belt 120 is lowered from the conveying position to the retracted position by the elevating mechanism, and the head cap 49 is moved to the back side by the cap opening / closing mechanism 108. The nozzle surface 40 of the cartridge 2 is closed. Thereby, the printer apparatus 1 returns to the state before printing shown in FIG.

  As described above, in the head cartridge 2 provided in the printer apparatus 1, the deaeration port 51 is provided on the upper surface of the ink channel 42 of the print head 2 shown in FIG. 1, and the ink channel 42 is passed through the deaeration port 51. Since the air accumulated in the inside is deaerated, the air accumulated in the ink flow path 42 can be appropriately removed without ejecting ink i containing air from the ink ejection nozzle 40a of the nozzle surface 40. Is possible. Therefore, in the printer apparatus 1, the mechanism for degassing the head cartridge 2 has a simple configuration, prevents an increase in the size of the entire apparatus, and suppresses wasteful consumption of the ink i, while preventing the print head 22 described above. The air accumulated in the ink flow path 42 can be appropriately deaerated. In the printer apparatus 1, it is possible to perform an appropriate printing operation on the recording paper P by improving the ejection reliability of the ink i by the head cartridge 2.

  Incidentally, the above-described print head 22 has a configuration in which the deaeration ports 51 are arranged at both ends of the ink flow path 42 in the longitudinal direction. However, the present invention is not necessarily limited to such a configuration, and the ink supply port 41 is disposed at one end portion in the longitudinal direction of the ink flow path 42 and the other end portion in the longitudinal direction of the ink flow path 42. The structure by which the deaeration port 51 is arrange | positioned may be sufficient.

  In the printer apparatus 1 described above, the head cartridge 2 can be attached to and detached from the printer main body 3 and the ink tank 4 can be attached to and detached from the cartridge main body 5. The tank 4 is handled as a consumable item and can be easily replaced. However, the present invention is not necessarily limited to such a configuration, and may be a configuration in which the head cartridge 2 is provided integrally with the printer body 3, and the ink tank 4 is provided integrally with the cartridge body 5. It may be a configured.

  Further, the liquid discharge head of the liquid discharge apparatus according to the present invention is of a full line type in which the nozzle member 9 is formed to be long over the width of one side of the recording paper. However, the present invention is not limited to this, and the nozzle member The present invention can also be applied to a serial type in which 9 is formed shorter than the width of one side of the recording paper and reciprocates in the width direction of the recording paper.

  Further, in the above description, an example applied to an ink jet printer has been described. However, the present invention is not limited to this, and the liquid contained in the liquid chamber of the liquid ejection head is ejected as droplets from the liquid ejection nozzle. Anything can be used. For example, the present invention can be applied to a facsimile machine or a copying machine whose recording system is an inkjet system.

  The liquid ejected from the nozzles of the liquid ejection head of the liquid ejection apparatus is not limited to ink, and any other liquid ejection apparatus can be used as long as it can form a dot row or a dot by ejecting the liquid in the liquid chamber. Can be applied. For example, the present invention can be applied to a liquid discharge device for discharging a DNA-containing solution onto a pallet in DNA identification or the like, or a liquid discharge device for discharging a liquid containing conductive particles for forming a wiring pattern of a printed wiring board. Can do.

It is explanatory drawing of the ink jet printer used directly for implementation of the liquid discharge performance maintenance method by this invention. It is a perspective view which shows the bubble sensor arrange | positioned in the ink delivery pipe | tube of the said inkjet printer. It is explanatory drawing which shows the Example which clamps the said ink delivery pipe | tube with a holding member, and forms a substantially parallel surface. It is explanatory drawing which shows 2nd Embodiment of the said inkjet printer. It is a flowchart explaining operation | movement of the liquid discharge performance maintenance method of the said inkjet printer. 1 is a perspective view showing an ink jet type printer apparatus to which the present invention is applied. FIG. 7 is a perspective view illustrating a state where an ink tank is mounted on a cartridge main body mounted on the printer apparatus illustrated in FIG. 6. FIG. 4 is a cross-sectional view illustrating a state where a head cartridge is mounted on the printer body. It is sectional drawing which shows the state which opened the front side of the outer casing of the printer main body shown in FIG. FIG. 9 is a cross-sectional view for explaining an operation of forming a print image on recording paper by operating the printer main body shown in FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer apparatus 2 ... Head cartridge 3 ... Printer main body 4 ... Ink tank 5 ... Cartridge main body 21 ... Ink supply part 22 ... Print head 29 ... Ink adjustment valve 40 ... Nozzle surface 40a ... Ink discharge nozzle 49 ... Head cap 51 ... Detaching Vent 110 ... Display panel 152 ... Waste ink tank 159 ... Ink delivery pipe 200 ... Tube 201 ... Electric pump 202 ... Bubble sensor 203 ... Defoaming filter 204 ... Control unit 205 ... Holding member 206 ... Rib 207 ... Timer i ... Ink

Claims (7)

The liquid is discharged from the liquid discharge head that discharges the liquid supplied from the liquid container containing the predetermined liquid from the liquid discharge nozzle formed on the nozzle surface, and the bubbles mixed in the liquid are removed to remove the liquid. A method for maintaining liquid ejection performance that reduces ejection defects,
The liquid is discharged from the liquid discharge head to remove bubbles in the liquid,
The liquid discharge is characterized in that after the start of the bubble removal, the bubble removal is continued until a predetermined time elapses after detecting the absence of bubbles in the liquid discharged from the liquid discharge head. Performance maintenance method. The liquid is discharged from the liquid discharge head that discharges the liquid supplied from the liquid container containing the predetermined liquid from the liquid discharge nozzle formed on the nozzle surface, and the bubbles mixed in the liquid are removed to remove the liquid. A method for maintaining liquid ejection performance that reduces ejection defects,
The liquid is discharged from the liquid discharge head to remove bubbles in the liquid,
After the start of the bubble removal, after detecting the absence of bubbles in the liquid discharged from the liquid discharge head, until at least the volume of liquid contained in the liquid discharge head has been discharged, A method for maintaining liquid ejection performance, wherein the bubble removal is continued. A liquid container containing a predetermined liquid;
A liquid discharge head for supplying the liquid contained in the liquid container and discharging the liquid from a liquid discharge nozzle formed on the nozzle surface;
A liquid delivery pipe connected to a liquid discharge port for discharging the liquid in the liquid discharge head and serving as a discharge flow path for the liquid;
A liquid ejecting apparatus provided on the liquid delivery pipe and comprising suction means for sucking the liquid in the liquid ejecting head,
The liquid delivery pipe is provided with detection means for detecting the state of the liquid in the liquid delivery pipe,
A control means for controlling the operation of the suction means based on the state of the liquid detected by the detection means is provided,
A liquid ejecting apparatus comprising: a measuring unit that measures a time during which the suction unit is stopped and sends a control signal to the control unit.   The liquid ejecting apparatus according to claim 3, wherein the detection unit is an optical sensor that optically detects the presence or absence of bubbles in the liquid flowing in the liquid delivery pipe.   The liquid ejecting apparatus according to claim 3, wherein the detection unit is a pressure sensor that detects presence or absence of bubbles in the liquid flowing in the liquid delivery pipe by a pressure change.   4. The liquid according to claim 3, wherein a liquid reflux line is configured to connect the liquid discharge port of the liquid delivery pipe to the liquid container and return the liquid discharged from the liquid discharge head to the liquid container. Discharge device.   The liquid ejecting apparatus according to claim 3, wherein the detecting unit is disposed immediately after a liquid discharge port of the liquid ejecting head.

Images