Abstract:
An ink jet recorder includes: a recording head; an ink cartridge detachably attached to the recording head; a purging device for purging the nozzle of the recording head; and a carriage for holding the recording head and conveying it across the width of a recording medium and an area outside the medium; and a controller. Provided in an area outside the medium is an ink receiver for receiving the ejection of ink for flushing. The controller controls the carriage with the recording head in such a manner that, before purging is started by the purging device, the carriage is moved to a position where the recording head opposes the ink receiver and then the recording head ejects ink for flushing. Air bubbles generated in the joint passage formed between the recording head and the ink cartridge when they are fitted to each other, can be displaced into the recording head by flushing, and the thus flushed air bubbles can be suctioned together with ink by purging.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an ink jet recorder for recording images etc., on recording media with ejected ink, and more specifically relates to an ink jet recorder having a purging device for purging the recording head and a flushing device for removing air bubbles inside the recording head. 
     2. Description of the Related Art 
     Ink jet printers have been typically known as ink jet recorders for use in recording characters, images etc., on recording media such as paper etc., with ejected ink. 
     As shown in FIG. 8, a typical ink jet printer uses an ink cartridge P 1  for storage of ink which can be removably mounted in a recording head unit P 3  having a recording head P 2 , so that ink cartridge P 1  is attached to recording head P 2  by mounting it to recording head unit P 3 . The mounted ink cartridge P 1  supplies recording head P 2  with ink, which in turn is ejected from an ejection nozzle P 4  provided in recording head P 2 , thus performing printing of characters etc. Provided inside recording head P 2  is ink channels (not shown) which are defined with side-walls made up of piezoelectric elements so that ink compressed by the alternation of the intra-channel volume will be ejected from nozzle P 4 . 
     When predetermined conditions are satisfied during the operation of the ink jet printer, for example, automatically or by user interaction, ejecting nozzle P 4  is subjected to a so-called purging operation, by which ink inside nozzle P 4  is sucked from the ejection side of ejecting nozzle P 4 , that is, nozzle tip P 5  having openings or ejection holes (not shown). 
     The specific operation of purging comprises: covering nozzle tip P 5  with a suction cap P 6 ; applying a negative pressure within suction cap P 6  by an unillustrated suction pump; and sucking the ink from ink cartridge P 1  and recording head P 2  by way of suction cap P 6  so as to displace the ink to the outside. 
     This purging operation is performed when an unused ink cartridge P 1  is replaced or initially attached, in order to initially introduce the ink inside unused cartridge P 1  into recording head P 2 . Alternatively, it is also performed in order to prevent mal-ejection of ink during the operation of the ink jet printer. A purging operation for the former purpose in particular is referred to as an initial purge or initial ink introduction purge. 
     When the user has mounted an unused ink cartridge P 1  as a replacement or for initial setup, air will enter recording head P 2 . More specifically, there is a commutation passage between the ink feed port on the ink cartridge P 1  and the ink inlet port on the recording head P 2 , and air will enter this commutation passage when ink cartridge P 1  is mounted into recording head P 2 . 
     In a typical configuration, a filter is provided at the ink inlet port of recording head P 2 , aimed mainly at the prevention of foreign substances entering recording head P 2 . 
     Accordingly, when the aforementioned purging operation (initial purge) is performed after replacement of an ink cartridge P 1  so that ink is rapidly sucked from the nozzle tip P 5  of ejection nozzle P 4  by means of suction cap P 6 , air within the aforementioned commutation passage rushes in and passes through the filter attached at the ink inlet port of recording head P 2 , generating a number of air bubbles. The air bubbles rapidly mix with the ink inside recording head P 2 , resultantly leaving air bubbles inside the ink channels and ejection nozzle P 4 . 
     In general, when ink jet printers of this type are shipped from the factory, recording head P 2  is charged with a liquid for preservation (to be referred to as a storage solution) having properties similar to the ink but containing no pigment and dye. 
     For this reason, also when the aforementioned purging operation is performed after the user has initially attached an ink cartridge P 1  to recording head P 2 , air inside the aforementioned commutation passage rushes in and passes through the filter attached at the ink inlet port of recording head P 2 , and the air rushes in and mixes with the ink inside recording head P 2 , resultantly generating a great deal of air bubbles and hence leaving the air bubbles inside the ink channel and ejection nozzle P 4 . 
     In ink jet printers of this type, there are cases where ink cartridge P 1  has a filter at its ink feed port. This filter prevents entrance of foreign substances inside cartridge P 1  into recording head P 2  and also prevents ink leakage by making use of the surface tension of ink acting on the pores of the filter. Also in this case, when, upon the implementation of purging, ink inside ink cartridge P 1  rushes through the filter provided at the ink feed port, into the aforementioned commutation passage containing air, a great number of air bubbles will be generated, resultantly leaving the air bubbles inside the ink channels and ejection nozzle P 4 . 
     Air bubbles remaining inside the ink channels and ejection nozzle P 4  hinder the increase in pressure for ink to be ejected out, causing mal-ejection and hence degradation of recording image. 
     SUMMARY OF THE INVENTION 
     In view of what has been discussed above, it is therefore an object of the present invention to provide an ink jet recorder which can prevent residual air bubbles within the recording head after replacement or initial attachment of an ink cartridge. 
     In accordance with one aspect of the invention, an ink jet recorder is provided which comprises: a recording head having an ink inlet port, a filter provided at the ink inlet port and a nozzle for ejecting ink onto recording media; an ink cartridge detachably attached to the recording head for supplying ink to the inlet port of the recording head; a purging device for purging the nozzle from the exterior of the recording head; a carriage for holding the recording head and conveying it across the width of a recording medium and an area outside thereof; an ink receiver disposed in the area outside the width of the recording medium, for receiving ink ejected for flushing; and a controller which controls the carriage and recording head in such a manner that, before purging is started by the purging device, the carriage is moved to a position where the recording head opposes the ink receiver and therein the recording head ejects ink for flushing. 
     The ink jet recorder of the invention, is configured so that the controller makes the nozzle active so as to eject ink toward the ink receiver for flushing operation before the purging device starts actual purging. Therefore, in accordance with the ink jet recorder of the invention, after replacement or initial attachment of an ink cartridge, initial introduction of ink can be completed successfully without leaving any air bubbles within the recording head. 
     As has been already described, in an ink jet printer of this type, when the ink cartridge is attached to the recording head, air will enter the joint passage between the ink feed port of the ink cartridge and ink inlet port of the recording head for receiving the ink supply from the ink feed port. Therefore, if purging is performed immediately after replacement or initial attachment of an ink cartridge as in the conventional configuration, the air having entered the joint passage will rush in and pass through the filter attached to the ink inlet port of the recording head, and mix rapidly with the liquid (ink or the aforementioned storage solution), producing a great deal of air bubbles. Further in the case where a filter is also attached to the ink feed port of the ink cartridge, ink inside the ink cartridge will rush in and pass through the filter attached at the ink feed port of the ink cartridge, and rapidly mix with the air within the joint passage, producing a further increased amount of air bubbles. 
     In contrast, in the ink jet recorder of the invention, the controller controls the recording head and carriage so as to perform the flushing operation by ejecting ink toward the ink receiver before purging. Therefore, even if air has entered the joint passage between the ink feed port of the ink cartridge and the ink inlet port of the recording head during attachment of the ink cartridge to the recording head, the air within the joint passage and the ink inside the ink cartridge can be moved to the recording head side, for example a manifold thereof by ink ejection performed prior to purging. The movement of the air occurs at a very gentle speed which would be unfeasible using a suction pump, because a negative pressure in the joint passage produced when the flushing is performed by ejecting ink toward the ink receiver is generally lower than that produced when the purging device purges the nozzle. 
     Consequently, in accordance with the ink jet recorder of the invention, in the case where the ink inlet port of the recording head for receiving the ink supply from the ink feed port of the ink cartridge has a filter (to be referred to hereinbelow as filter Fa), air having entered the joint passage is moved into the recording head, by making the air pass through filter Fa at a gentle speed so as not to generate a number of air bubbles, so that purging can be implemented under conditions in which no air resides on either side of filter Fa. As a result, it is possible to prevent rapid mixing of air with the liquid in front of and behind filter Fa while purging is performed. Thus, it is possible to remarkably inhibit the generation of air bubbles during purging after replacement or initial attachment of an ink cartridge. 
     In accordance with the ink jet recorder of the invention, also in the case where the ink cartridge has a filter (to be referred to hereinbelow as filter Fb) provided at the ink feed port thereof, ink inside the ink cartridge can be moved to the joint passage by making the ink pass through filter Fb at a gentle speed so as not to generate air bubbles, so that purging can be implemented under conditions in which no air resides on either side of filter Fb. As a result, it is possible to prevent rapid mixing of air with the liquid in front of and behind filter Fb while purging is performed. Thus, it is possible to remarkably inhibit the generation of air bubbles during purging after replacement or initial attachment of an ink cartridge. In this document, the term “joint passage” means a passage formed between the filter Fb provided at the ink feed port on the ink cartridge and the filter Fa provided at the ink inlet port on the recording head if the recording head and the cartridge have these filters, respectively. 
     The amount of ink to be ejected during the operation of the controller may be set as follows: That is, the ink jet recorder is configured so that the controller controls the recording head in such a manner that the recording head ejects flushing ink in an amount greater than the volume of the passage defined by the ink feed port and the ink inlet port when the ink cartridge is mounted on the recording head. In accordance with the ink jet recorder having this configuration, air residing within the joint passage between the ink feed port of the ink cartridge and the ink inlet port of the recording head can be assuredly be drawn into the recording head before purging is started so that it is possible to fill with ink both sides of filter Fa attached at the ink inlet port of the recording head as well as both sides of filter Fb attached at the ink feed port of the ink cartridge. Accordingly, it is possible to reliably inhibit the generation of air bubbles after purging has been performed. 
     It is possible to configure the controller so as to perform driving of the recording head for flushing every time prior to implementation of purging. However, it is more efficient and advantageous if the driving of the recording head is adapted to be performed only when purging is first performed after the attachment of the ink cartridge to the recording head. As a result flushing operation will be performed only in a state where air has entered the joint passage between the ink cartridge and the recording head, e.g., after replacement of an ink cartridge, after initial attachment of an ink cartridge or any other reason. Therefore, it is possible to minimize the ejected amount of ink from the nozzle for reasons other than recording onto recording media as well as to minimize the time to be spent for purging. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an illustrative view showing the interior construction of an ink jet printer of an embodiment; 
     FIG. 2 is a perspective view showing a recording head unit of an embodiment; 
     FIG. 3 is an illustrative sectional view showing the state in which an ink cartridge is attached to a recording head unit; 
     FIG. 4 is an illustrative view showing the configuration of a suction device of an embodiment; 
     FIG. 5 is a block diagram showing an electric configuration of an ink jet printer of an embodiment; 
     FIG. 6 is a flowchart showing the control operation to be performed in the controller of an embodiment; 
     FIG. 7 is a flowchart showing the purging operation performed by the controller of an embodiment; and 
     FIG. 8 is an illustrative view showing the configurations of a recording head unit and ink suction device of a conventional ink jet printer. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Now, the ink jet printer to which the embodiment of the invention is applied will be described with reference to the accompanying drawings. It should be noted that the present invention will not be limited to the embodiment described hereinbelow, and can be realized in various forms as long as it belongs to the scope of the claims of the present application. 
     First, FIG. 1 is an illustrative view showing the interior construction of an ink jet printer  1  in accordance with this embodiment. 
     As shown in FIG. 1, in ink jet printer  1 , a carriage  8  is slidably supported by a guide rod  11  and guide member  12  while fixed to a belt  13  so that it can be driven by a CR motor (carriage drive motor)  16  to move in a reciprocating manner. Attached to this carriage  8  is a recording head unit  17  having a recording head  18  for performing recording such as printing characters etc. 
     This recording head unit  17  is an ink jet type to achieve recording by ejecting four colors of ink (cyan c, magenta m, yellow y and black b where the alphabetical symbols c, m, y and b represent cyan, magenta, yellow and black, respectively) onto a recording sheet of paper P as the recording medium. 
     Recording head  18  located on the recording side of recording head unit  17 , has four ejection heads  21   y,    21   m,    21   c  and  21   b  (which will be generally referred to as ejection heads  21  hereinbelow) in order to eject the respective colors of ink, as shown in FIG.  2 . Each ejection head  21  has an ejection surface  23  with many (e.g. 64) ejection holes (nozzles)  24  as openings. As indicated by two-dot chain lines in FIG. 2, four ink cartridges  22   y,    22   m,    22   c  and  22   b  (which will be generally referred to as ink cartridges  22  hereinbelow) for supplying respective nozzles  21  with associated ink, are removably attached to the cartridge mounting port formed on the side of recording head unit  17  opposite recording head  18  (on the left side in FIG.  2 ). 
     Referring to FIG. 3, each ejection head  21  provided for recording head  18  of recording head unit  17  is structured of a well-known actuator which is formed by machining piezoelectric material, and has many ink ejection passages therein, which will be referred to as channels  41 . Each channel  41  is connected to an ink ejection hole  24  on the end face, i.e., on the ejection surface  23  side (the left side in FIG.  3 ). 
     All channels  41  of ejection head  21  communicate at their ink in-flow side end (on the right side in FIG. 3) with a manifold  42  provided inside recording head  18 . This manifold  42  has an opening, i.e., ink inlet port  43  for recording head  18 , with a mesh-like filter  44  covering the opening in order to prevent foreign substances such as dust etc. from entering recording head  18 . Fixed around the outer rim of filter  44  is an approximately annular joint  45  made up of elastic material such as rubber etc. 
     In recording head  18  of recording head unit  17 , the aforementioned manifold  42 , ink inlet port  43 , ink filter  44  and joint  45  are provided for each ejection head  21 . 
     As seen in FIG. 3, ink cartridge  22  has an ink feed port  46 , at which a mesh-like filter  47  aimed primarily at preventing ink leakage is pressed and fixed in front of joint  45 , by means of an approximately annular, resin-made adapter  48 . 
     In this configuration of recording head unit  17 , when ink cartridge  22  is mounted, adapter  48  of ink cartridge  22  comes in close contact with joint  45  of recording head  28 , as seen in FIG. 3, and thus the attachment of an ink cartridge  22  to recording head  18  is completed. Then, ink is supplied from ink feed port  46  of ink cartridge  22  to ink inlet port  43  of recording head  18  by way of the joint passage (designated at  49 ) defined by the hollow of adapter  48  and the hollow of joint  45 . The thus fed ink is supplied from manifold  42  inside recording head  18  to all channels  41  of ejection head  21 . Voltages are applied to ejection head  21  so as to change the passage widths of channels  41  to thereby eject ink through selected ejection holes  24 . 
     In this embodiment, the volume of manifold  42  formed inside recording head  18  is designed to be greater than the volume of joint passage  49  which is formed when ink cartridge  22  is attached to recording head  18 . The reason for manifold  42  having a greater volume than joint passage  49  is to maintain a sufficient volume in manifold  42  to trap air having moved from joint passage  49  when flushing is performed. In addition, when ink jet printer  1  is shipped from the factory, the interior of recording head  18 , including channels  41  and manifold  42  for each ejection head  21  is filled up with a storage solution. 
     Returning to FIG. 1, a conveyer mechanism LF for conveying a recording sheet of paper P is provided at a position opposite recording head  18 . This conveyer mechanism LF is driven by an LF motor (conveyer motor)  30  (see FIG. 5) so as to rotate a platen roller  25 , which, as it rotates, conveys a recording sheet of paper P. 
     Provided on one side is a maintenance/restoration mechanism RM for maintaining and restoring the ink ejecting operation of recording head  18 . 
     This maintenance/restoration mechanism RM comprises: a suction device  26 ; preservation caps  27  covering individual ejection surfaces  23  of ejection heads  21  so as to prevent dryout of ink when ink jet printer  1  is unused; and a wiper  28  for wiping ejection surfaces  23  of ejection heads  21 . Here, this suction device  26  functions to implement initial introduction of ink from a newly mounted ink cartridge  22  into recording head  18  upon its replacement or its initial setup, and also to solve the mal-ejection of ink occurring due to dryout of ink, mixing of air bubbles into the ink, ink droplets adhering to ejection surface  23  of ejection heads  21  and/or any other malfunctions occurring during the operation of ink jet printer  1 . 
     Suction device (or purging device)  26  includes: as shown in FIGS. 1 and 4, a suction cap  33  which can come into and out of close contact with ejection surface  23  of each ejection head  21  of recording head  18 ; and a suction pump  34  for sucking ink through suction cap  33  when suction cap  33  is in close contact with recording head  18 . In this suction device  26 , a cam member  36  which is driven by a cam drive motor  35  (see FIG.  5 ), moves suction cap  33  and wiper  28  forward to recording head  18 , and then suction pump  34  is activated to achieve the operation of sucking (or purging) through suction cap  33 . 
     Wiper  28  is located on the suction cap  33  side, as shown in FIGS. 1 and 4, and is used to wipe off the ink having adhered on ejection surfaces  23  of ejection heads  21 . 
     Further, as shown in FIG. 1, collecting member (ink receiver)  29  made up of porous material for collecting waste ink is provided on the side opposite to maintenance/restoration mechanism RM, with conveyer mechanism LF therebetween. This collecting member  29  is used for a flushing operation in which, ink is ejected with ejection head  21  set to collecting member  29  so as to remove air bubbles and/or mixed color ink residing within the interior of recording head  18 . 
     Referring next to FIG. 5, the electric configuration of ink jet printer  1  will be explained. 
     As shown in FIG. 5, a controller  50  for controlling the operation of ink jet printer  1  is essentially composed of a well-known microcomputer having a CPU  50   a,  a ROM  50   b  and a RAM  50   c  and an input/output portion  50   d,  etc. 
     Connected to input/output portion  50   d  are: a cartridge replacement key  51  which the user will press for replacement of an ink cartridge  22  or when a fresh ink cartridge  22  is attached for initial setup; switches through which the user can instruct suction device  26  to start a sucking operation; cartridge sensing switches  52  for detecting whether cartridges  22  are mounted or not; a purge HP sensor  53  for detecting whether suction pump  34  is in its home position; a PE sensor  54  for detecting the leading edge of recording sheet of paper P; a CR position sensor  56  for detecting the position of carriage  8 . 
     Cartridge sensing switches  52 , are provided in the aforementioned cartridge mounting portion of recording head unit  17 , one for each ejection head  21 , and each cartridge sensing switch will be turned on when the associated ink cartridge  22  is mounted and adapter  48  on ink cartridge  22  fits in close contact with joint  45  of recording head  18 . 
     Connected further to input/output portion  50   d  are: ejection heads  21 , especially actuators formed therein for ejecting ink; CR motor  16  for moving carriage  8 ; LF motor  30  for driving conveyer mechanism LF; cam drive motor  35  driving cam member  36  for moving suction device  26 ; indicators for displaying the current operation conditions etc.; suction pump  34  for sucking ink through suction cap  33 , and the like. 
     Referring next to flowcharts shown in FIGS. 6 and 7, description will be made of the processing sequence of controller  50 , which is implemented in the thus configured ink jet printer  1  of this embodiment when the user replaces one ink cartridge  22  associated with one of ejection heads  21 , or when the user mounts one ink cartridge  22  associated with one of ejection heads  21  for initial setup. 
     Controller  50  implements the control sequence shown in FIG. 6, repeatedly every predetermined period of time. When this control is started, first, it is judged at Step (to be abbreviated as S, hereinbelow)  10  whether cartridge replacement key  51  is pressed and turned on by the user. If the judgment is negative (S 10 : No), the control process is ended without performing anything. 
     On the other hand, if it is determined at S 10  that cartridge replacement key  51  is turned on (S 10 : Yes), carriage  8  is moved to the cartridge replacement position at the following step, i.e., S 20 . More specifically, whilst the position of carriage  8  is detected based on the signal from CR position sensor  56 , CR motor  16  is operated so as to move carriage  8  to the predetermined cartridge replacement position. 
     When carriage  8  has been thus moved to the cartridge replacement position, the operation is waited for at S 30  until any of cartridge sensing switches  52  change from the OFF-state to the ON-state. 
     When, at S 30 , it is determined that one of cartridge sensing switches  52  has changed from the OFF-state to the ON-state (S 30 : Yes), the system determines that the ejection head  21  associated with the cartridge sensing switch  52  which has been turned on, has been fitted with new ink cartridge  22  as a replacement or as the initial setup. Then this operation is followed by S 40  where carriage  8  is moved to the position (to be referred to as flushing position) where ejection heads  21  face collecting member  29  shown in FIG. 1, in the same procedure as in S 20 . 
     When carriage  8  has been moved to the flushing position in the above way, all channels  41  of ejection head  21  (the ejection head  21  for which replacement or initial setup of an ink cartridge  22  has been made, and which will be hereinbelow referred to as initial purge target ejection head  21 ) corresponding to the cartridge sensing switch  52  which has been determined at S 30  as having changed to the ON-state are activated only during a predetermined time T, so as to eject ink from the initial purge target ejection head  21 , toward collecting member  29 , or perform an operation of flushing. Here, in this embodiment the predetermined time T is set up to be equal to the time required for ink in an amount equal to the volume of manifold  42 , to be ejected. This is because ink, which contains air and is located in joint passage  49 , should be conveyed into manifold  42  by the flushing operation. 
     Next, at S 60 , in the same procedure as S 20  described above, carriage  8  is moved to the position (to be referred to hereinbelow as purge position) where the initial purge target ejection head  21  opposes suction cap  33 . When carriage  8  has been moved to the purge position, a purging operation (an initial purge) shown in FIG. 7 will be implemented following S 70 , for purging initial purge target ejection nozzle  21 . 
     Once this purging is started, first, at S 121  shown in FIG. 7, cam drive motor  35  is activated so that suction cap  33  comes into close contact with ejection surface  23  of the initial purge target ejection head  21 . Subsequently, at S 122 , suction pump  34  is activated to generate a negative pressure within suction cap  33 . This generation of negative pressure causes suction pump  34  to suction ink from ejection surface  23  of the initial purge target ejection head  21  via suction cap  33 . 
     Next, at S 124 , upon the generation of a negative pressure, the built-in timer in the micro computer is started so as to clock the suction time of ink. 
     At S 125 , when it is determined that 5 seconds, for example, has elapsed, the operation goes to S 126  where the operation of suction pump  34  is stopped while cam drive motor  35  is activated so that suction cap  33  is pulled away from ejection surface  23  of the initial purge target ejection head  21 . Then, at the final step, i.e. S 127 , the ink which has been sucked from ejection surface  23  of the ejection head  21  during the steps S 122  to S 125  is discharged outside of suction pump  34  to end the purging operation. 
     The end of the purging operation shown in FIG. 7 is followed by S 80  of FIG. 6, where carriage  8  is moved to the preservation cap position in the same procedural order as in S 20 . Here, at the preservation cap position, carriage  8  will be located so that all nozzles  21  of recording head  18  oppose respective caps  27  (four caps in FIG.  1 ). After carriage  8  has been moved to the preservation cap position, this control is ended. 
     Returning to FIG. 6, in the case where the user replaced more than one ink cartridge  22  corresponding to ejection heads  21  or mounted more than one fresh cartridges as the initial setup at the step S 20  where carriage  8  had been moved to the cartridge replacement position, all the ejection heads  21  which correspond to the replaced or newly mounted ink cartridges  22  are made active for predetermined time T, at S 50  in FIG.  6 . Then, the operations for initial purge at S 60  and S 70  in FIG. 6 are successively performed for each of the ejection heads  21 . 
     In ink jet printer  1  of this embodiment, the purging operation shown in FIG. 7 will also be performed when other purge execution conditions are satisfied, other than the timing of S 70  of FIG.  6 . Examples of these conditions include cases where the aforementioned purge key is operated to command the execution of purging of any of ejection heads  21 , and where the cumulative usage time of the ink jet printer  1  reaches a predetermined time. 
     In this embodiment, the CPU serves as the purge controller. 
     As has been detailed, in ink jet printer  1  in accordance with this embodiment, when replacement of ink cartridge(s)  22  or newly mounting of ink cartridge(s)  22  has been detected based on the ON/OFF state of cartridge sensing switch(es)  52  (S 30 : Yes), purging (initial purge) of suction device  26  is performed for ejection head(s)  21  corresponding to replaced or newly mounted ink cartridge(s)  22  (S 60 , S 70 ). In particular, ejection head(s)  21  is/are adapted to be made active to eject ink for the predetermined time T before execution of the initial purge (S 40 , S 50 ). 
     Therefore, in accordance with ink jet printer  1  of this embodiment, after replacement of an ink cartridge(s)  22 , or after initial attachment of an ink cartridge(s)  22 , initial introduction of ink can be completed without leaving any air bubbles within ejection head(s)  21 . 
     Illustratively, when the user mounts ink cartridge  22  into recording head  18 , air will enter joint passage  49  (see FIG. 3) between ink feed port  46  of ink cartridge  22  and ink inlet port  43  of recording head  18 . If purge is directly performed after replacement of ink cartridge  22  or after initial attachment of an ink cartridge  22 , the air having entered the joint passage  49  rushes in and passes through filter  44  attached at ink inlet port  43  of recording head  18 , and/or rapidly mixes with the liquid (the ink or the aforementioned storage solution inside manifold  42 ) inside recording head  18 , producing many air bubbles. Further, the ink inside ink cartridge  22  rushes through filer  47  attached at ink feed port  46  of ink cartridge  22 , and abruptly becomes mixed with air within joint passage  49 , producing a further increased amount of air bubbles. 
     In contrast, in the case of ink jet printer  1  of this embodiment, before purging, ejection head  21  is made active for the predetermined time T required for ink in an amount equal to the volume of manifold  42 , to be ejected. The negative pressure in the joint passage produced when the recording head ejects the ink for the flushing is lower than that produced when the purging device purges the nozzle. Accordingly, air having entered joint passage  49  during mounting ink cartridge  22  can be made to pass through filter  44  at a gentle speed which will not cause air bubbles to arise and be transferred into recording head  18  (more specifically, manifold  42 ), and at the same time, ink from newly mounted ink cartridge  22  can, pass through filters  47  and  44  at a gentle speed which will not generate air bubbles, and be transferred into recording head  18 . Even though a small amount of air bubbles are generated in or transferred into the manifold, the air bubbles may be sucked out of the ejection heads  21  by the following purging operation. 
     In ink jet printer  1  of this embodiment, since purging is performed under the conditions in which no air exists on either side of filters  44  and  47 , it is possible to prevent air and the liquid from mixing in front of and behind both filters  44  and  47  during purging. Thus, it is possible to markedly inhibit the generation of air bubbles during purging (initial purging) after replacement of an ink cartridge  22  or after initial attachment of an ink cartridge  22 . 
     Accordingly, in accordance with ink jet printer  1  of this embodiment, while entrance of foreign substances into recording head  18  can be blocked by filter  44  attached at the ink inlet port  43  of recording head  18 , leakage of ink from ink cartridge  22  can be prevented by filter  47  attached at ink feed port  46  of ink cartridge  22 . And, it is also possible to remarkably inhibit generation of air bubbles when purging is performed after replacement of an ink cartridge  22  or after initial attachment of an ink cartridge  22 . 
     Further, it is also possible to configure a system in which the implementation (driving of ejection head  21 ) of S 40  and S 50  in FIG. 6 is performed before every time purging operation shown in FIG. 7 is implemented. However, as in this embodiment, it is advantageous if the implementation of S 40  and S 50  of FIG. 6 is adapted to be performed only after replacement of an ink cartridge  22  or after initial attachment of an ink cartridge  22  (that is, only when the purging operation is first performed after attachment of an ink cartridge  22  to recording head  18 ). This is because, in this case, ejection head  21  can be made active only when air is contained within joint passage  49  between ink cartridge  22  and recording head  18 , so that it is possible to save the amount of ink which will be ejected from ejection head  21  for purposes other than recording on a recording sheet of paper P. 
     Although the description of the above embodiment has been made in the case where the invention is applied to an ink jet printer, the present invention can be without doubt, applied in the same manner to other appliances using an ink jet type recording apparatus (such as facsimile machines).