Patent Publication Number: US-7905566-B2

Title: Liquid ejecting device

Description:
This application claims priority from Japanese Patent Application No. 2006-268497 filed on Sep. 29, 2006, the entire subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a liquid ejecting device which ejects liquid as a liquid droplet. This invention is particularly effective when applied to an inkjet recording device (inkjet printer). 
     2. Description of Related Art 
     An inkjet recording device forms an image on a recording medium by ejecting a liquid (e.g., ink), in the form of liquid droplets, from an ejecting head (recording head) onto the recording medium (e.g., a sheet). 
     In such an inkjet recording device, if the liquid droplet is ejected irregularly from the ejecting head (nozzle) because the nozzle for ejecting the liquid droplet (ink) is clogged or the like, then a desired image is not formed on the recording medium. Accordingly, it is desirable to periodically check the ejecting head to detect an ejection failure. One example of how to periodically check the ejecting head to detect an ejection failure is to eject a liquid droplet from the ejection head into/onto an ejection failure detecting unit. 
     In an invention disclosed in Japanese Unexamined Patent Application Publication No. 9-24621, a pair of electrodes are provided in an ejection failure detecting unit, so that when a liquid droplet is ejected to the ejection failure detecting unit, the liquid droplet causes a short circuit between the pair of electrodes. In the invention disclosed in this publication, it is detected whether or not the liquid droplet is ejected irregularly from an ejecting head (ejection failure of the ejecting head), by determining whether or not electric current flows between the pair of electrodes. 
     Since liquid such as ink generally has a low conductivity, there is only a small difference between the value of a current flowing between the pair of electrodes when they are in the short-circuited state (i.e., the liquid droplet passes between the electrodes), and the value of a current flowing between the pair of electrodes when they are not in the short-circuited state (i.e., no liquid droplet passes between the electrodes). 
     Owing to this, it is difficult to accurately detect an ejection failure of the ejecting head with the invention disclosed in the above publication because the determination as to whether or not the electric current flows between the pair of electrodes is not reliable. 
     SUMMARY OF THE INVENTION 
     A liquid ejecting device including an ejecting head having an ejecting nozzle through which the ejecting head ejects a liquid in the form of a liquid droplet, a liquid droplet receiving portion having an outlet that is open for forming a meniscus using the liquid droplet ejected from the ejecting head, and a meniscus determining unit for determining whether or not the meniscus is formed at the outlet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the appearance of a multi-function device according to a first embodiment of the invention; 
         FIG. 2  is a schematic illustration showing an overall configuration of an inkjet recording device; 
         FIG. 3  is an enlarged view showing a lower surface of a recording head; 
         FIG. 4  is an explanatory illustration showing a configuration of an ejection failure detecting unit; 
         FIG. 5  is a block diagram showing an electric configuration of the multi-function device; 
         FIG. 6  is a flowchart showing an ejection failure detecting process which is executed by a control device of the multi-function device; and 
         FIG. 7  is an explanatory illustration showing a configuration of an ejection failure detecting unit according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present invention are described below with reference to the drawings. 
     A liquid ejecting device according to a first embodiment of the present invention is applied to a multi-function device having a printer function, a scanner function, a copier function, and a facsimile function.  FIG. 1  is a perspective view showing the appearance of a multi-function device  1 . 
     As shown in  FIG. 1 , the multi-function device  1  has a scanner unit  2  at an upper portion for reading an image of an original, and a casing  1   a  at a lower portion. An inkjet recording device  3  (see  FIG. 2 ) is provided at an upper portion inside the casing  1   a . The inkjet recording device  3  forms (records) an image on a sheet of recording media  20 . 
       FIG. 2  is a schematic illustration, as seen from the front of the multi-function device  1  showing an overall configuration of the inkjet recording device  3 .  FIG. 3  is an enlarged view showing a lower surface of a recording head  11 . 
     As shown in  FIG. 2 , the inkjet recording device  3  includes the recording head  11  having ink nozzles  11   a  (see  FIG. 3 ) for ejecting ink droplets, as well as an ink tank (not shown) for supplying ink to the recording head  11 . 
     The recording head  11  is mounted on a carriage  4 . As shown in  FIG. 3 , a plurality of ink nozzles  11   a  (150 nozzles in this embodiment) are arrayed in a row along a sub-scanning direction (sheet conveying direction), thereby defining a nozzle array. The sub-scanning direction is a direction going into and coming out of the drawing sheet of  FIG. 2 . A plurality of the nozzle arrays (in this embodiment, four arrays) are provided along a main scanning direction (left and right direction in the drawing). 
     The ink nozzles  11   a  of the nozzle array located at the left side of the recording head  11  in  FIG. 3  eject black (Bk) ink. The ink nozzles  11   a  of the remaining three nozzle arrays respectively eject cyan (C) ink, yellow (Y) ink, and magenta (M) ink, as indicated in  FIG. 3 . 
     The inkjet recording device  3  records and forms an image on a sheet  20  by ejecting ink of the various colors on the sheet  20  while the recording head  11  moves back and forth in the main scanning direction. 
     As shown in  FIG. 2 , a guide bar  24  is a guide member extending in the main scanning direction of the carriage  4  (recording head  11 ) so as to guide the movement of the carriage  4 . The carriage  4  is coupled to an endless belt  25 . 
     The endless belt  25  extends between a pulley  26  (right side of  FIG. 2 ) and an idle pulley  27  (left side of  FIG. 2 ). The pulley  26  is rotated by a carriage motor (CR motor)  28 . 
     When the carriage motor  28  rotates the endless belt  25 , the carriage  4  (i.e., the recording head  11 ) moves parallel to the left and right direction in the drawing (main scanning direction). 
     A timing slit  29 , which extends parallel to a longitudinal direction of the guide bar  24 , is disposed in the vicinity of the guide bar  24 . The timing slit  29  has linear apertures (slits) having a common predetermined width. The linear apertures (slits) are arranged with a predetermined pitch in a longitudinal direction of the timing slit  29 . 
     The carriage  4  has a detector (not shown) including a photo interrupter in which a light-emitting element and a light-receiving element face each other with the timing slit  29  interposed therebetween. The detector and the timing slit  29  constitute a linear encoder (carriage feed encoder)  30  (see  FIG. 5 ) that detects a moving distance (position) of the carriage  4  (recording head  11 ). 
     As shown in  FIG. 2 , the area where the carriage  4  moves back and forth along (moves parallel to) the guide bar  24  is divided into three sections: a recording section where recording is performed on a sheet  20 ; a standby section where no recording is performed; and a gap adjustment section. 
     The standby section is provided in the vicinity of an end of the guide bar  24  near the pulley  26 . The carriage  4  stands by in the standby section when neither recording nor maintenance is performed. At other times, the recording head  11  is checked in the standby section to see if there is an ink-droplet-ejection failure. In addition, a recovery operation is executed in the standby section to remove dried ink in the ink nozzle  11   a  (see  FIG. 3 ) or a foreign substance trapped in the ink nozzle  11   a . In this way, normal ink ejection can be performed. 
     The gap adjustment section is for the operation of a gap adjustment unit (not shown). The gap adjustment unit adjusts the size of a gap between a sheet  20  and the ink nozzles  11   a  (see  FIG. 3 ) of the recording head  11 , to an optimum value. 
     In the standby section, a cap  21  is disposed at a position facing the recording head  11  when the carriage  4  is stopped at a position for the recovery operation (right end position in  FIG. 2 ). The cap  21  includes a cover member that covers one of the four arrays of ink nozzles  11   a  provided at the recording head  11 . The cap  21  is driven by a cap driving unit  22 . 
     The cap  21  and the cap driving unit  22  are arranged below the recording head  11  in the standby section. When the carriage  4  is stopped at the position for the recovery operation, the cap driving unit  22  moves the cap  21  upward so that the cap  21  contacts the lower surface of the recording head  11  to cover an array of ink nozzles  11   a.    
     In contrast, when the carriage  4  (recording head  11 ) is moved during a recording operation, the cap driving unit  22  moves the cap  21  downward so as to uncover the ink nozzles  11   a.    
     A waste ink tank  32  (see  FIG. 4A ) is connected to the cap  21 , for collecting unnecessary ink using a suction pump  34  (see  FIG. 4A ) described below. A recovery operation is performed when the suction pump  34 , which is connected to the cap  21  via a switching mechanism  36 , is operated while the ink nozzles  11   a  are covered by the cap  21 . The recovery operation is performed so as to remove dried ink or a foreign substance from the ink nozzle  11   a . The suction pump  34  then sends the dried ink and foreign substance that were removed from the nozzle  11   a  to the waste ink tank  32 . 
     In addition, an ejection failure detecting unit  16  is provided adjacent to the cap  21  in the main scanning direction of the carriage  4 . The ejection failure detecting unit  16  detects any ink-droplet-ejection failure of the recording head  11 . 
       FIG. 4  is an explanatory illustration showing a configuration of the ejection failure detecting unit  16 . 
     As shown in  FIG. 4A , the ejection failure detecting unit  16  includes a plurality of ink droplet receiving portions  31  each having a funnel-like shape, a suction pump  34  for generating a negative pressure, and a pressure sensor  35 . 
     The ink droplet receiving portions  31  are disposed in the standby section below the recording head  11  (see  FIG. 2 ). The number of ink droplet receiving portions  31  corresponds to the number of ink nozzles  11   a  in each nozzle array. In this embodiment, there are 150 ink droplet receiving portions  31 . Every ink droplet receiving portion  31  is treated with a water repellant finish. 
     As shown in  FIG. 4B , the ink droplet receiving portions  31  are separately formed and arranged along an array corresponding to the direction of the arrays of ink nozzles  11   a  (i.e., sub-scanning direction). 
     As shown in  FIG. 4A , each of the ink droplet receiving portions  31  has a triangular cross section as seen in the sub-scanning direction. At the lower end of each ink droplet receiving portion  31 , an outlet  31   a  is formed. Each outlet  31   a  is open so that a meniscus can be formed using by an ink droplet that is ejected (not for the purpose of printing) from the recording head  11 . 
     An opening  31   b  is formed at an upper side of the ink droplet receiving portion  31 , and has an ellipsoidal shape. The major axis direction thereof is substantially parallel to the main scanning direction. Each of the ink droplet receiving portions  31  is formed in a funnel-like shape. The major and minor axes thereof are continuously and smoothly reduced in length from the upper opening  31   b  toward the outlet  31   a  while maintaining the ellipsoidal opening shape of the ink droplet receiving portion  31 . 
     The diameter of the outlet  31   a  of this embodiment is 0.05 to 0.1 mm. Also, the gap between the adjacent outlets  31   a  are substantially equivalent to the gap between the adjacent ink nozzles  11   a  in each of the nozzle arrays. 
     As shown in  FIG. 4A , a common ink collecting path  33  is coupled to every outlet  31   a . The ink collecting path  33  connects the ink droplet receiving portions  31  to the waste ink tank  32 . The ink collecting path  33  runs through the suction pump  34 , the switching mechanism  36 , and the pressure sensor  35 . The suction pump  34  generates a negative pressure in the ink collecting path  33 . The pressure sensor  35  detects the pressure in the ink collecting path  33  between the ink droplet receiving portions  31  and the suction pump  34 . 
       FIG. 5  is a block diagram showing an electric configuration of a control device of the multi-function device  1 . 
     As shown in  FIG. 5 , the control device is a microcomputer having a central processor  70  provided with a CPU, ROM, and RAM. The central processor  70  can transmit data to, and receive data from, various sensors, (e.g., the pressure sensor  35 , a temperature sensor  73 , and the inkjet recording device  3 ) through a bus  71  and an application specific integrated circuit (“ASIC”)  72 . 
     The ROM of the central processor  70  has a predetermined computer program stored therein. In accordance with the program stored in the ROM, and based on information provided by the various sensors, the CPU (1) controls rotation of the carriage motor  28 , which moves the carriage  4  in a sliding manner, (2) controls ejection of the ink droplets from the ink nozzles  11   a  in the recording head  1 , and (3) controls the suction pump  34 . 
       FIG. 6  is a flowchart showing process for detecting an ejection failure, which is executed by the control device of the multi-function device  1 . This process (shown in the flowchart in  FIG. 6 ) is executed before the recording operation is performed on a sheet  20 . In particular, the process shown in  FIG. 6  is performed before the ink droplets are ejected onto a sheet  20 . 
     In the ejection failure detecting process shown in  FIG. 6 , each nozzle array is checked for ejection failure. In this embodiment, the Bk ink nozzle array, the C ink nozzle array and the M ink nozzle array are sequentially checked in that order. 
     When the process shown in  FIG. 6  is started, the carriage  4  is moved to the position where the ejection failure detecting unit  16  (ink droplet receiving portions  31 ) is provided in the standby section (see  FIG. 2 ) ( FIG. 6 , S 110 ). 
     In particular, as shown in  FIG. 4A , the carriage  4  is moved to a position above the ink droplet receiving portions  31  such that the position above the nozzle array (ink nozzles  11   a ) of the Bk ink is shifted from the position of the outlets  31   a  by a predetermined distance in the main scanning direction (major axis direction of the openings  31   b ) ( FIG. 6 , S 110 ). 
     When the carriage  4  is moved to the position above the ink droplet receiving portions  31  ( FIG. 6 , S 110 ), some ink droplets are ejected from each ink nozzle  11   a  of the Bk ink nozzle array ( FIG. 6 , S 120 ). These ink droplets are ejected to the ink droplet receiving portions  31  flow to the outlets  31   a , thereby forming menisci at the outlets  31   a.    
     When the ink droplets are ejected from the ink nozzles  11   a  in step S 120 , the suction pump  34  generates a negative pressure (in this embodiment, 1 to 2 kPa) for detecting the menisci ( FIG. 6 , S 130 ). 
     When the suction pump  34  generates the negative pressure for detecting the menisci in step S 130 , the presence of the menisci formed at the outlets  31   a  is determined on the basis of a pressure value in the ink collecting path  33  detected by the pressure sensor  35  ( FIG. 6 , S 140 ). 
     In this embodiment, if the pressure value in the ink collecting path  33  is smaller than a predetermined threshold value, then it is determined that menisci are formed at all outlets  31   a  ( FIG. 6 , S 140 : YES). In contrast, if the pressure value in the ink collecting path  33  is larger than the threshold value, then it is determined that there is at least one outlet  31   a  without a meniscus ( FIG. 6 , S 140 : NO). 
     If it is determined that the menisci are formed at all outlets  31   a  ( FIG. 6 , S 140 : YES), it means that no ejection failure exhists in the nozzle array of the Bk ink. In other words, the ink droplets are normally ejected from the nozzle array of the Bk ink. This result (detection result) is then stored in a storage unit such as the RAM ( FIG. 6 , S 150 ). 
     On the other hand, if it is determined that there is an outlet  31   a  without a meniscus ( FIG. 6 , S 140 : NO), it means that there is at least one ink nozzle  11   a  having an ejection failure in the nozzle array of the Bk ink. This result (detection result) is then stored in the storage unit such as the RAM ( FIG. 6 , S 155 ). 
     After the result that an ejection failure is present or that no ejection failure is present is stored in the storage unit (S 150  and S 155 ), the suction pump  34  generates a negative pressure which is larger than the negative pressure generated in step S 130  (negative pressure for detecting menisci), so as to collect (suck) any menisci formed at the outlets  31   a  to the waste ink tank  32  ( FIG. 6 , S 150 ). In step S 150 , negative pressure of 30 to 50 kPa is generated. 
     After the negative pressure for collecting the menisci is generated ( FIG. 6 , S 150 ), it is determined whether or not a nozzle array remains that has not been checked for ejection failure ( FIG. 6 , S 170 ). 
     In the above description, since only the nozzle array for the Bk ink has been checked, the determination in step S 170  is YES ( FIG. 6 , S 170 : YES), and the process returns to step S 110  for the next nozzle array. In this case, the steps of S 110  to S 160  are repeated for the nozzle array of the C ink. Then the steps S 110  to S 160  are repeated for the Y ink, and finally for the nozzle array of the M ink. 
     After the steps S 110  to S 160  for the nozzle array of the M ink are completed, it is determined in step S 170  that all the nozzle arrays have been checked for ejection failure ( FIG. 6 , S 170 : NO). The presence of a nozzle array (ink nozzles  11   a ) having an ejection failure is then determined based on the detection result stored in steps S 150  and S 155  ( FIG. 6 , S 180 ). 
     If it is determined that no nozzle array has an ejection failure ( FIG. 6 , S 180 : NO), the process shown in  FIG. 6  is ended. In contrast, if it is determined that any nozzle array has an ejection failure ( FIG. 6 , S 180 : YES), the above-described recovery operation is performed to remove any ink dried or any foreign substance trapped in any nozzle array (ink nozzles  11   a ) for which an ejection failure was detected ( FIG. 6 , S 190 ). The process shown in  FIG. 6  is then ended. 
     In this embodiment, if an ejection failure is detected in the nozzle array of the Bk ink, the recovery operation is executed for the nozzle array of the Bk ink. Similarly, if an ejection failure is detected in any of the nozzle arrays of the C ink, Y ink, and M ink, the recovery operation is executed respectively for those nozzle arrays for which ejection failure was detected. 
     In this embodiment, the ejection failure of the recording head  11  is detected by determining whether menisci are formed at the outlets  31   a  of the ink droplet receiving portions  31  after the ink droplets are ejected from the recording head  11  into the ink droplet receiving portions  31 . 
     In particular, when the ink droplets are ejected from the recording head  11  to the ink droplet receiving portions  31 , the ink droplets cause menisci to be formed at the outlets  31   a . Therefore, when the menisci are formed at the outlets  31   a , it can be assumed that an ejection failure of the recording head  11  has not occurred. In contrast, when a meniscus is not formed, it can be assumed that an ejection failure of the recording head  11  has occurred. 
     Therefore, with this embodiment, an ejection failure of the recording head  11  can be determined merely by determining whether menisci fail to be formed at the outlets  31   a . This improves the reliability of the inkjet recording device  3 . 
     Also, in this embodiment, the outlets  31   a  are closed by the menisci when the menisci are formed at the outlets  31   a . Hence, if the suction pump  34  generates the appropriate negative pressure, then the pressure in the ink collecting path  33  is reduced. On the other hand, when a meniscus is not formed, the pressure in the ink collecting path  33  is not substantially reduced even though the suction pump  34  operates, because at least one of the outlets  31   a  is open. 
     Therefore, whether or not a meniscus fails to be formed can be determined merely by an appropriate reduction in the pressure in the ink collecting path  33 . 
     Also, in this embodiment, since each of the ink droplet receiving portions  31  has the triangular cross section with one of the three vertices being directed downward (see  FIG. 4 ), the ink droplets ejected to the ink droplet receiving portions  31  flow to the outlets  31   a . This facilitates the movement of the ink droplets to the outlets  31   a.    
     In addition, since each ink droplet receiving portion  31  is treated with the water repellant finish, the ink droplets do not stick to the ink droplet receiving portion  31 , and thus easily flow to the outlet  31   a.    
     As shown in  FIG. 4A , when the ink droplets are ejected from the recording head  11  to the outlet  31   a , the ink droplets are ejected to an inclined wall (guide wall) formed between the upper opening  31   b  and the outlet  31   a . Accordingly, the ink droplets ejected to the ink droplet receiving portion  31  are prevented from passing through the outlet  31   a  to the ink collecting path  33 . 
     When the ink droplets are ejected from the recording head  11  to each outlet  31   a , multiple ink droplets are ejected from each nozzle. Accordingly, the multiple ink droplets combine to form a large ink droplet by the time they reach the outlet  31   a , thereby reliably forming a meniscus at the outlet  31   a.    
     In this embodiment, since the recording head  11  ejects the ink droplets to the ink droplet receiving portions  31  separately for each nozzle array, whether or not menisci are formed at the outlets  31   a  can be determined for each color (individual nozzle array). 
     Since only one nozzle array at a time is provided above the receiving portions  31 , the number of ink droplet receiving portions  31  do not have to correspond to the total number of ink nozzles  11   a  in all of the nozzle arrays combined, thereby reducing the manufacturing cost. 
     In this embodiment, the ejection failure of the recording head  11  can be detected without using the electrodes as disclosed in the related art. Accordingly, this embodiment can be implemented at a lower cost than the invention disclosed in the related art. 
     In the first embodiment, whether or not the menisci are formed is determined based on the pressure reduction in the ink collecting path  33 . In a second embodiment, whether or not the menisci are formed is determined based on light which is reflected by the meniscus formed at the outlet  31   a .  FIG. 7  is an explanatory illustration showing a configuration of an ejection failure detecting unit  50  according to the second embodiment. 
     A light-transmittable member  52  made of glass, plastic, or the like, which transmits light, is disposed below the outlet  31   a , in the ink collecting path  33 . An optical meniscus detector  54 , including a light emitter and a light receptor, is disposed below the light-transmittable member  52 . 
     In this embodiment, when the ink droplet is ejected to the ink droplet receiving portion  31  in the ejection failure detecting process (see  FIG. 6 , S 120 ), the light emitter of the optical meniscus detector  54  emits light, instead of the step of S 130  of  FIG. 6 . 
     In this embodiment, the light emitted from the light emitter is reflected by the meniscus (ink droplet) formed at the outlet  31   a  and the light receptor of the optical meniscus detector  54  receives the light reflected by the meniscus. 
     Once the light is emitted from the light emitter of the optical meniscus detector  54 , the presence of the meniscus (presence of an ejection failure) is determined based on whether or not the light is reflected back to the light receptor by the meniscus. 
     In particular, when a meniscus is formed at each outlet  31   a , the light emitted from the light emitter is reflected by the meniscus back to the light receptor. On the other hand, when a meniscus is not formed, the light emitted from the light emitter passes the outlet  31   a , and hence the light is not reflected back to the light receptor. 
     Therefore, with the use of the optical meniscus detector  54  of this embodiment, it can be determined whether the menisci are formed. Thus, this embodiment provides advantages similar to those of the first embodiment. 
     Although, in the first embodiment, the suction pump  34  generates a negative pressure in the ink collecting path  33 , and the pressure sensor  35  detects the pressure value in the ink collecting path  33 , the suction pump  34  may generates a positive pressure, instead. 
     In addition, while the ejection failure detecting unit  16  is disposed in the standby section in the first embodiment as shown in  FIG. 2 , it is not limited thereto. The ejection failure detecting unit  16  may alternatively be disposed in the gap adjusting section. In such a case, the suction pump  34  may generate negative pressure in the ink collecting path  33  as well as perform the recovery operation by sucking ink and the like that adheres to the ink nozzle  11   a  in a manner similar to the first embodiment. A plurality of suction pumps may also be used for these functions. 
     The inkjet recording device  3  may be an on-carriage type of device in which the ink tank is mounted on the carriage  4 . Alternatively, the inkjet recording device  3  may be another type of device in which ink is supplied from an ink tank provided outside the carriage  4  to the recording head  11  through a tube. 
     Meanwhile, the proof stress of the meniscus may vary with the ambient temperature. In particular, the meniscus may become rigid and difficult to break when the ambient temperature is low. When the ambient temperature is high, the meniscus may become soft and easily broken. 
     Owing to this, a meniscus-determining threshold value for determining whether or not the meniscus is formed may be corrected based on information provided by the temperature sensor  73  (see  FIG. 5 ). 
     For example, the meniscus-determining threshold value can be derived (corrected), by previously storing in the storage unit a meniscus-determining map that represents a relationship between the ambient temperature and the meniscus-determining threshold value. The meniscus-determining map may then be searched based on the information provided by the temperature sensor  73 . 
     Accordingly, whether or not the meniscus is formed at the outlet  31   a  can be accurately determined. 
     While the opening shape of the ink droplet receiving portion  31  of the above-described embodiments is ellipsoidal, it is not limited thereto. The opening shape of the ink droplet receiving portion  31  may be another shape, such as rectangular or circular. 
     While the major and minor axes of the ink droplet receiving portion  31  of the above-described embodiments are reduced in length toward the outlet  31   a  from the upper opening  31   b , it is not limited thereto Instead, only one of the major and minor axes may be reduced in length. 
     While the cross section of the ink droplet receiving portion  31  of the above-described embodiment is triangular as seen in either the sub-scanning direction or the main scanning direction (as shown in  FIGS. 4A and 4B ), it is not limited thereto. For example, only the cross section as seen in the sub-scanning direction may be triangular. 
     While the ink droplet receiving portion  31  has a funnel-like shape in the above-described embodiment, it is not limited thereto. In addition to the outlet  31   a , the ink droplet receiving portion  31  is only required to have an inclined wall (guide wall) which is inclined with respect to an ink droplet ejecting direction (a vertical direction) so as to guide the ink droplet toward the outlet  31   a.    
     Accordingly, in the above described embodiments, when the liquid droplet is ejected from the ejecting head to the liquid droplet receiving portion, a meniscus of the liquid droplet is formed at the outlet. When the meniscus is formed at the outlet, it is assumed that an ejection failure of the ejecting head has not occurred. In contrast, when the meniscus is not formed at the outlet, it is assumed that an ejection failure of the ejecting head has occurred. 
     Therefore, the ejection failure of the ejecting head can be accurately determined merely by determining the whether the meniscus is formed at the outlet, thereby improving the reliability of the liquid ejecting device. 
     While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the inventions as defined in the following claims.