Abstract:
A fluid cartridge is disclosed. The fluid cartridge includes a flexible bag body to store a fluid, a nozzle to discharge the fluid and a membrane inside the bag body to assist in the collapse of the bag body during discharging of the fluid.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to an ink cartridge used in an ink jet printer. 
       BACKGROUND 
       [0002]    High speed production ink jet printers typically implement a fluid cartridge (or ink bag). Such a cartridge employs a flexible casing that is deformable in accordance with consumption of ink therein. However, fluid cartridges tend not to empty fully when external air pressure is applied. This is mainly due to wrinkles forming on the creases of the side walls that do not flatten out as the bag empties, thus trapping fluid when emptying. 
         [0003]    Accordingly, a mechanism to enable full emptying of a fluid cartridge is desired. 
       SUMMARY 
       [0004]    In one embodiment, a fluid cartridge is disclosed. The fluid cartridge includes a flexible bag body to store a fluid, a nozzle to discharge the fluid and a membrane inside the bag body to assist in the collapse of the bag body during discharging of the fluid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    A better understanding of the present invention can be obtained from the following detailed description in conjunction with the following drawings, in which: 
           [0006]      FIG. 1  illustrates a top view of one embodiment of a fluid cartridge; 
           [0007]      FIG. 2  illustrates a rear view of one embodiment of a fluid cartridge; 
           [0008]      FIGS. 3A and 3B  illustrate embodiments of a permeable membrane; and 
           [0009]      FIGS. 4A-4C  further illustrate rear view embodiments of a fluid cartridge. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    A mechanism to enable full emptying of a fluid cartridge is described. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form to avoid obscuring the underlying principles of the present invention. 
         [0011]    Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
         [0012]      FIG. 1  illustrates a top view of one embodiment of a fluid cartridge  100 . In one embodiment, fluid cartridge  100  includes a bag body  102  formed by flexible sheet members and configured in a manner, for example, that flexible sheet members such as gas-barrier laminate films each formed by depositing aluminum on a polyethylene film are overlapped, and heat welding seal is performed along the outer periphery of the overlapped sheet members to form a welded portion. 
         [0013]    Fluid (e.g., ink used for printing) is stored within cartridge  100  and is discharged via a nozzle  105  at one end edge of body  102 . In one embodiment, nozzle  105  is formed by a hard material, such as composite resin. Body  102  includes sidewalls  107 , sidewall creases  110  and a membrane  120  attached to sidewall creases  110 . In one embodiment, membrane  120  is an elastic permeable membrane that is implemented to pull in the sidewalls  107  such that the side walls  107  fold and collapse along respective creases  110  to aid in the collapse of cartridge  100 . In other embodiments, membrane  120  may be comprised of any elastic material that does not interact with the ink within cartridge  100 . 
         [0014]      FIG. 2  illustrates a rear view of one embodiment of fluid cartridge  100  in which membrane  120  is attached to creases  110 . As shown in  FIG. 2 , sidewalls  107  are folded, and the cartridge  100  material is fused with membrane  120  inserted in between. Accordingly, membrane  120  is comprised of material that is able to withstand fusing temperatures. 
         [0015]      FIG. 3A  illustrates one embodiment of a membrane  120  used to pull in side walls  107 . In this embodiment, vertical bands  310  are elastic, while horizontal bands  320  are not. In such an embodiment, horizontal bands  320  are implemented to hold vertical bands  310  in place, with the gap between bands  310  enabling the cartridge  100  material to come together to provide a better fuse at crease  110 . In a further embodiment, vertical bands  310  are fused perpendicular to the crease  110  line to permit crease  110  to fold properly. In still a further embodiment, the angle (σ) between bands  310  and  320  is 90°. However in other embodiment, σ may vary between 0° and 90°. 
         [0016]      FIG. 3B  illustrates another embodiment of a membrane  120  having circular cutouts  330 . In this embodiment, cutouts  330  have a horizontal orientation to enable membrane  120  to stretch. In one embodiment, membrane  120  exerts an elastic force in a perpendicular direction to that of the crease  110  to aid in collapsing of the bag.  FIGS. 4A-4C  illustrate embodiments of a rear view of fluid cartridge  100  during various stages of ink fill. 
         [0017]    As shown in  FIGS. 4A-4C  elastic membrane  120  pull together sidewalls  107  at crease  110 , aiding in the collapse of fluid cartridge  100 . For instance, when bag body  102  is at the fullest position, the membrane is exerting a maximum elastic force on the side wall creases  110 .  FIG. 4A  shows cartridge  100  at the fullest position, with the elastic force being measured at X. As ink is drained from bag body  102 , membrane  120  exerts a force in the collapsing direction to assist in the draining. 
         [0018]      FIG. 4B  illustrates a further embodiment of cartridge  100  after fluid has been discharged. As shown in  FIG. 4B , the dimensions of bag body  102  are unchanged. However, the elastic force of membrane  120  is measured at Y, where X&gt;Y. has moved in a perpendicular direction marked by a location at a distance Y.  FIG. 4C  illustrates yet another embodiment of cartridge  100  after fluid has been completely drained. In this embodiment, bag body  102  is at its flattest position with the dimensions remaining unchanged. However, membrane  120  is exerting a minimal elastic force measured at Z, where X&gt;Y&gt;Z. 
         [0019]    Whereas many alterations and modifications of the present invention will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that any particular embodiment shown and described by way of illustration is in no way intended to be considered limiting. Therefore, references to details of various embodiments are not intended to limit the scope of the claims, which in themselves recite only those features regarded as essential to the invention.