Patent Publication Number: US-2006012651-A1

Title: Inkjet cartridge

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2004-55761, filed Jul. 16, 2004, the disclosure of which is hereby incorporated herein by reference in its entirety.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present general inventive concept relates to an inkjet cartridge, and more particularly, to an inkjet cartridge capable of preventing a crack phenomenon of a head chip.  
      2. Description of the Related Art  
      An inkjet cartridge is a device for printing a predetermined image on a recording medium by ejecting ink stored in an interior part toward an exterior in a droplet shape, and is typically used in a state where the inkjet cartridge is mounted on a carriage of an inkjet printer, which is movable in a width direction of the recording medium.  
      Such an inkjet cartridge includes a cartridge body provided with a predetermined space therein to store the ink, a head chip mounted on a bottom surface of the cartridge body to eject the ink stored in the cartridge body to a desired position of the recording medium through a nozzle portion thereof, and a lid mounted on an upper portion of the cartridge body to seal an open portion of a top surface of the cartridge body.  
      Specifically, the cartridge body is provided with a negative pressure maintaining unit for maintaining the inside of the cartridge body at a predetermined negative pressure, and a filter for filtering the ink supplied into the head chip at a lower portion of the cartridge body. At this time, the negative pressure maintaining unit conventionally uses foam.  
      In addition, a head chip for ejecting the ink is attached to a lower portion of the filter, i.e., a bottom surface of the cartridge body using an adhesive agent such as a sealant.  
      Further, the lid is fusion-bonded to the upper portion of the cartridge body by an ultrasonic wave, etc., the lid including an inner lid provided with an ink supply hole and an outer lid mounted on an upper portion of the inner lid.  
      Therefore, a conventional inkjet cartridge is assembled by the following order and comes onto the market.  
      First, when the filter is mounted in the cartridge body, an operator attaches the head chip to the bottom surface of the cartridge body using an adhesive agent etc.  
      Then, after the head chip is attached to the cartridge body, a predetermined amount of foam is inserted into the cartridge body.  
      Continuously, after the foam is inserted, the inner lid is fusion-bonded to the upper portion of the cartridge body.  
      Then, after the inner lid is fusion-bonded, a predetermined amount of ink is introduced into the cartridge body through the ink supply hole formed at the inner lid.  
      Then, after the ink is introduced into the cartridge body, the outer lid is fusion-bonded to the upper portion of the cartridge body, i.e., the upper portion of the inner lid, by the ultrasonic wave. When the assembly of the inkjet cartridge is completed, the operator finally performs impact and drop tests for the assembled inkjet cartridge, and then the inkjet cartridges come onto the market.  
      However, such a conventional inkjet cartridge has various problems.  
      First, since the conventional inkjet cartridge is provided with the head chip directly attached to the cartridge body, an impact applied from an exterior of the inkjet cartridge during the impact and drop tests is directly transmitted to the head chip. As a result, the head chip has a problem in that a crack is often generated therein. Therefore, the cracked head chip not only makes a state of the ink ejection unstable but also causes leakage of the ink.  
      In addition, the foam is inserted in the conventional inkjet cartridge to absorb ultrasonic energy for fusion bonding while the outer lid and the cartridge body are fusion-bonded. Although bubbles due to the ultrasonic wave are not generated at a portion where the foam is inserted, there occurs a problem in that, when the outer lid and the cartridge body are ultrasonically bonded, the ultrasonic energy for the fusion bonding is directly transmitted to the head chip attached to the cartridge body and the ink at the upper portion of the head chip along the cartridge body, because no means for absorbing the ultrasonic energy is provided around the head chip of the inkjet cartridge, i.e., at the lower portion of the filter. Therefore, a great deal of bubbles are generated in the ink contained in the head chip and the ink located at the upper portion of the head chip by the transmitted ultrasonic energy, thus the bubbles are fully filled in the ink supply hole of the head chip and the nozzle portion, at which the ink is ejected, thereby lowering reliability of the ink ejection.  
     SUMMARY OF THE INVENTION  
      The present general inventive concept provides an inkjet cartridge capable of minimizing an impact applied to a head chip during impact and drop tests for the inkjet cartridge.  
      The present general inventive concept also provides an inkjet cartridge capable of minimizing generation of bubbles by absorbing ultrasonic energy applied around a head chip by a certain amount.  
      Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.  
      The foregoing and/or other aspects and advantages of the present general inventive concept may be achieved by providing an inkjet cartridge including a cartridge body provided with an ink storing space to store ink therein, a lid mounted on an upper portion of the cartridge body to seal the cartridge body, a head chip mounted on a lower portion of the cartridge body to eject the ink stored in the cartridge body, and at least one elastic member mounted on the cartridge body to absorb an impact transmitted to the head chip.  
      A plurality of elastic members may be mounted around the head chip.  
      The elastic members can be mounted at both sides of the head chip.  
      The elastic members can be mounted around the head chip and at corners of the cartridge body, respectively.  
      The elastic members can be mounted around the head chip and on edges of the cartridge body, respectively.  
      The elastic members may be formed of rubber or silicone.  
      The foregoing and/or other aspects and advantages of the present general inventive concept may also be achieved by providing an inkjet cartridge including a cartridge body provided with an ink storing space to store ink therein, a lid mounted on an upper portion of the cartridge body to seal the cartridge body, a head chip mounted on a lower portion of the cartridge body to eject the ink stored in the cartridge body, at least one elastic member mounted on the cartridge body to absorb an impact transmitted to the head chip, and a flexible printed circuit board electrically connected to edges of the head chip and covering edges and the elastic member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is a perspective view illustrating an inkjet cartridge according to an embodiment of the present general inventive concept;  
       FIG. 2  is an enlarged perspective view of a portion A of  FIG. 1 ;  
       FIG. 3  is an exploded perspective view in which an FPC is separated from the inkjet cartridge shown in  FIG. 1 ;  
       FIG. 4  is an exploded perspective view in which a head chip and an elastic member are separated from the inkjet cartridge shown in  FIG. 3 ;  
       FIG. 5  is a partial cross-sectional view of taken along a line I-I′ of  FIG. 1 ;  
       FIG. 6  is a perspective view illustrating an inkjet cartridge according to an embodiment of the present general inventive concept;  
       FIG. 7  is a perspective view illustrating an inkjet cartridge according to an embodiment of the present general inventive concept; and  
       FIG. 8  is a perspective view illustrating an inkjet cartridge according to an embodiment of the present general inventive concept. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.  
      Hereinafter, an inkjet cartridge  20  according to embodiment of the present general inventive concept will be described in more detail with reference to FIGS.  1  to  8 .  
      Referring to  FIGS. 1-5 , the inkjet cartridge  20  includes a cartridge body  21  provided with an ink storing space to store ink therein, a lid mounted on an upper portion of the cartridge body  21  to seal the cartridge body  21 , a head chip  25  mounted on a lower portion of the cartridge body  21  to eject the ink stored in the cartridge body  21 , and an elastic member  30 a mounted on the cartridge body  21  to absorb an impact transmitted toward the head chip  25 . The inkjet cartridge  20  may include a flexible printed circuit (FPC)  26  having an opening  28  through which nozzles of the head chip  25  are exposed. The FPC  26  may have a conductive line  27  formed therein to electrically connect the head chip  26  to an external circuit to eject the ink through the nozzles of the head chip  26 .  
      Specifically, the cartridge body  21  is formed in a shape of enclosure, and provided with an ink supply passage  22  at its lower portion and a hole to receive the ink supplied from an external source at its upper portion. Therefore, the ink supplied from the external source is introduced through the hole, and then supplied to the head chip  25  through the ink supply passage  22 .  
      In addition, a filter (not shown) is mounted at an upper side of the ink supply passage  22  to filter the ink, and the filtered ink is supplied into the head chip  25 .  
      Further, a unit to maintain a negative pressure (not shown) is installed at the upper portion of the filter, i.e., in the cartridge body  21  to maintain an inside of the cartridge body at the negative pressure. Therefore, the ink stored in the cartridge body  21  does not arbitrarily leak due to such an interior negative pressure. At this time, the negative pressure maintaining unit can adopt a spring or foam, etc., to generate the negative pressure.  
      Meanwhile, the lid is fusion-bonded to the upper portion of the cartridge body  21  using a ultrasonic wave, etc., and includes an inner lid (not shown) having an ink supply hole, and an outer lid  24  mounted on an upper portion of the inner lid to hermetically seal the cartridge body  21 . Therefore, the inner lid is fusion-bonded to the cartridge body  21 , and then the outer lid  24  is fusion-bonded to the cartridge body  21  to seal the cartridge body  21 .  
      In addition, the head chip  25  to eject the ink is attached to the cartridge body  21  at the lower portion of the ink supply passage  22 , i.e., a bottom surface of the cartridge body  21  to communicate with the ink supply passage  22 . At this time, the head chip  25  can be attached to the cartridge body  21  by an adhesive agent, etc. Specifically, the head chip  25  includes a plurality of chambers (not shown) for receiving the ink supplied through the ink supply passage  22  by a certain amount, the nozzles (not shown) formed at a lower side of each chamber, ink ejection devices respectively installed at the chamber to eject the ink in the chambers through the nozzles according to external signals transmitted through a conductor formed therein and the conductive line  27  of the FPC  26 , and a plurality of pads to respectively apply a power source to each ink ejection device. At this time, the nozzles are formed at a center of the head chip, and each of the pads is formed at an edge of the head chip.  
      Meanwhile, the elastic member  30 a is formed of an elastic material such as rubber or silicone, etc., and functions to absorb the impact (at this time, “impact” represents herein to include not only a mechanical impact but also any wave or vibration, etc.) transmitted to the head chip  25  from an exterior or an interior of the cartridge body  21 . At this time, when the elastic member  30   a  is formed of the rubber, etc., the elastic member  30   a  is attached to the cartridge body  21  after the elastic member  30   a  is processed to have a predetermined shape. On the other hand, when the elastic member  30   a  is formed of the silicone, etc., the elastic member  30   a  is applied on the cartridge body  21  in a predetermined shape. In addition, the elastic member  30   a  may be mounted on any portion of the cartridge body  21  capable of blocking the impact transmitted to the head chip  25  from the exterior or the interior and absorbing the impact, since the elastic member  30   a  functions to absorb the impact from the exterior or the interior.  
      As shown in FIGS.  1  to  5 , the elastic member  30   a  can be mounted around the head chip  25 , i.e., on a peripheral portion of the head chip  25 . At this time, the elastic member  30   a  may be formed in a rectangular panel or a frame type provided with the opening having a size equal to the head chip at its center. Therefore, a crack phenomenon generated from a conventional inkjet cartridge is prevented since the impact applied from the exterior during the impact and drop tests for the cartridge  20  is blocked and absorbed by the elastic member  30   a  around the head chip  25  before the impact is applied to the head chip  25  by inserting the head chip  25  into the center of the elastic member  30   a  having the rectangular panel shape. In addition, a bubble problem caused by a conventional ultrasonic wave is minimized since the elastic member  30   a  is capable of absorbing ultrasonic energy generated and transmitted during the fusion bonding of the outer lid  24 .  
      As shown in  FIG. 6 , a second elastic member  30   b  can be mounted only may be on both sides of the head chip  25 . In this case, the elastic members  30   b  may be formed of an elongated rectangular plate type longer than the head chip  25 .  
      In addition, as shown in  FIG. 7 , the elastic member  30   a  and a third elastic member  30   c  may be mounted around the head chip  25  and at corners of the cartridge body  21 , respectively. In this case, the elastic member  30   a  ( FIG. 7 ) mounted around the head chip  25  is formed in the same shape as the elastic member  30   a  of  FIG. 1 , and the elastic member  30   c  mounted on the cartridge body  21  is formed in a shape of surrounding the corners of the cartridge body  21  or a protrusion shape protruded from the cartridge body  21  by a predetermined size. The second elastic member  30   b  of  FIG. 6  may be used together with the third elastic member  30   c . Therefore, when the elastic members  30   a  and  30   c  are mounted on the cartridge body  21 , the elastic members  30   a  and  30   c  are capable of absorbing twice the external impact transmitted through the corners of the cartridge body  21  while the impact and drop tests are performed. As a result, the external impact is not substantially transmitted to the head chip  25  or minimally transmitted.  
      In addition, as shown in  FIG. 8 , the elastic member  30   a  and a fourth elastic member  30   d  can be mounted around the head chip  25  and on edges of the cartridge body  21 , respectively. In this case, the elastic member  30   a  mounted around the head chip  25  is formed in the same shape as the elastic member  30   a    FIG. 1 , and the elastic member  30   d  mounted on the cartridge body  21  is formed in a shape of surrounding the edges of the cartridge body  21 . The second elastic member  30   b  of  FIG. 6  can be used together with the fourth elastic member  30   d . Therefore, when the elastic members  30   a  and  30   d  are mounted on the cartridge body  21 , the elastic members  30   a  and  30   d  are capable of absorbing twice the external impact transmitted through the edges of the cartridge body  21  during the impact and drop tests, similar to the third embodiment. Therefore, the head chip  25  is protected from the external impact, etc.  
      Meanwhile, the inkjet cartridge  20  is used in a state where it is mounted on a carriage (not shown), etc., of an inkjet printer movable in a width direction of a recording medium. Therefore, the carriage reciprocally moves the inkjet cartridge  20  in the width direction of the recording medium depending upon an image type to be formed on the recording medium. As a result, the inkjet cartridge  20  is reciprocally moved in the width direction of the recording medium by the carriage to form a predetermined image on the recording medium.  
      At this time, the inkjet cartridge  20  is not simply mounted on the carriage, but it is brought into electrical contact with the carriage to receive predetermined signals from the carriage, wherein one side of the inkjet cartridge  20  is brought into contact with one side of the carriage. Therefore, the inkjet cartridge  20  selectively ejects the ink stored therein to form the predetermined image on the recording medium depending upon the signals inputted through the carriage.  
      Meanwhile, the inkjet cartridge  20  is provided with a circuit board to electrically connect from one side of the cartridge body  21  brought into electrical contact with the carriage to the head chip  25  attached to the bottom surface of the cartridge body  21 . Therefore, the predetermined signals inputted through the carriage are transmitted to the devices including the pads of the head chip  25  through the circuit board, respectively. At this time, the circuit board can be the flexible printed circuit (FPC)  26 . In this connection, the FPC  26  may be electrically connected to some portions of the head chip  25 , i.e., edges of the head chip, through the conductive line  27 . In addition, the FPC  26  mounted on the cartridge body  21  may cover the elastic members  30   a ,  30   b ,  30   c , and  30   d  mounted on the edges of the head chip  25  and around the head chip  25 , respectively. In addition, the FPC  26  is provided with the opening  28  having a predetermined size to expose a portion, at which the nozzle is formed, of the head chip  25 , i.e., a center of the head chip.  
      Hereinafter, an assembly procedure and an operating effect thereof of the inkjet cartridge  20  of  FIGS. 1, 6 ,  7 , or  8  will be more specifically described. As an example for the purpose of description of the assembly procedure, the elastic member  30   a  is mounted only around (peripheral portion of) the head chip  25  as shown in FIGS.  1  to  5 , and the negative pressure maintaining unit uses the foam.  
      First, when the filter is mounted in the cartridge body  21 , the elastic member  30   a , such as rubber, is attached to a bottom surface of the cartridge body  21  using an adhesive agent, etc. When silicone is used as the elastic member  30   a , the silicone is applied on the bottom surface of the cartridge body  21  to be attached to the cartridge body  21 .  
      Then, after the elastic member  30   a  is attached, the head chip  25  is attached to the cartridge body  21  at a center of the elastic member  30   a.    
      Continuously, after the head chip  25  is attached, a predetermined amount of foam is inserted into the cartridge body  21 .  
      Then, after the foam is inserted, the inner lid is fusion-bonded to an upper portion of the cartridge body  21 .  
      Continuously, after the inner lid is fusion-bonded, a predetermined amount of ink is introduced into the cartridge body  21  through the ink supply hole formed at the inner lid.  
      Then, the ink is introduced, the outer lid is ultrasonically fusion-bonded to the upper portion of the cartridge body  21 , i.e., an upper portion of the inner lid. As a result, the assembly of the inkjet cartridge  20  is completed. Therefore, the impact and drop tests for the inkjet cartridge  20  assembled as above are finally performed, and then the inkjet cartridge  20  comes onto the market.  
      At this time, since the inkjet cartridge  20  is provided with the elastic member  30   a ,  30   b ,  30   c , or  30   d  around the head chip  25 , etc., when the impact and drop tests are performed, the impact applied from the exterior is previously blocked and absorbed by the elastic member  30   a ,  30   b ,  30   c , or  30   d  before the impact is applied to the head chip. Therefore, the crack phenomenon of a conventional head chip is prevented.  
      In addition, since the elastic member  30   a ,  30   b ,  30   c , or  30   d  also absorbs a certain amount of ultrasonic energy generated and transmitted during the fusion bonding of the lid, the bubbles in the ink generated by the ultrasonic energy are also remarkably reduced. Therefore, a reliability problem of the ink ejection due to the bubbles is fully prevented.  
      As described above, since the inkjet cartridge can be provided with the elastic member around the head chip  25 , etc., when the impact and drop tests are performed, the impact applied from the exterior is previously blocked and absorbed by the elastic member  30   a ,  30   b ,  30   c , or  30   d  before the impact is applied to the head chip. Therefore, since the external impact is not substantially transmitted to the head chip, the crack phenomenon of the conventional head chip is fully prevented.  
      In addition, since the elastic member  30   a ,  30   b ,  30   c , or  30   d  mounted on the cartridge body  21  also absorbs a certain amount of ultrasonic energy generated and transmitted during the fusion bonding of the lid, only a minimum amount of ultrasonic energy may be transmitted to the ink stored in the head chip of the cartridge body. Therefore, the bubbles in the ink generated by the ultrasonic energy are also remarkably reduced. Therefore, a reliability problem of the ink ejection due to the bubbles is fully prevented.  
      Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.