Abstract:
A print cartridge including a cartridge body, a fluid reservoir disposed within the cartridge body that receives and contains fluid, a fluid ejector chip comprising a plurality of heating elements that eject the fluid from the print cartridge, and a memory device that stores first data related to information regarding the number of times the print cartridge was remanufactured and second data related to information regarding the print yield of the print cartridge for each instance of cartridge remanufacture.

Description:
FIELD 
     This invention is related to inkjet printheads, and in particular, to systems and methods for determining yield of inkjet printheads. 
     BACKGROUND 
     Remanufactured—or recycled—printer cartridges are sent to a manufacturer who will restock the ink and replace or repair any parts that are damaged or not working correctly. When an inkjet cartridge is remanufactured or refilled, often the amount of ink in the remanufactured cartridge is not equivalent to the amount of ink that was provided by the original fill of that cartridge. This can be for a variety of reasons, including but not limited to the ink fill capability of the remanufacturer, technical issues with the used cartridge that may reduce the amount of ink it is capable of holding after remanufacture, and also simply the amount of ink the remanufacturer wishes to fill. 
     When this remanufactured cartridge is installed in a printer, there is a need for the printer to know how much ink is remaining in the cartridge. This information is used to provide a gauge to track ink remaining which can be communicated to the user. This information can also be used to indicate when a new cartridge should be purchased or shipped to the customer, or to disable function of the cartridge when a certain amount of ink has been used (i.e., if cartridge is empty). 
     Since the ink filled into a cartridge during remanufacture is not necessarily equivalent to the ink filled originally, the printer will be unable to determine this information for the remanufactured cartridge based on the information originally programmed into the cartridge memory. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a means to refill a cartridge with an arbitrary amount of ink. This amount of ink does not have to be related to the amount filled in the original cartridge. 
     This is accomplished by providing fields in the memory map of the inkjet cartridge that are programmed at the time of remanufacture. These fields are used by the printer FW when the reman cartridge is installed to determine the amount of ink in the remanufactured cartridge. 
     A print cartridge according to an exemplary embodiment of the present invention comprises: a cartridge body; a fluid reservoir disposed within the cartridge body that receives and contains fluid; a fluid ejector chip comprising a plurality of heating elements that eject the fluid from the print cartridge; and a memory device that stores first data related to information regarding the number of times the print cartridge was remanufactured and second data related to information regarding the print yield of the print cartridge for each instance of cartridge remanufacture. 
     An inkjet printer according to an exemplary embodiment of the present invention comprises: a housing; a carriage adapted to reciprocate along a shaft disposed within the housing; one or more printhead assemblies arranged on the carriage so that the one or more printhead assemblies eject ink onto a print medium as the carriage reciprocates along the shaft in accordance with a control mechanism, wherein at least one of the one or more printhead assemblies comprises: a printhead cartridge comprising: a cartridge body; an ink reservoir disposed within the cartridge body that receives and contains ink; an ink ejector chip comprising a plurality of heating elements that eject the ink from the ink reservoir; and a memory device that stores first data related to information regarding the number of times the printhead cartridge was remanufactured and second data related to information regarding the print yield of the printhead cartridge for each instance of cartridge remanufacture. 
     According to at least one embodiment, the first data comprises one or more first data fields, each first data field comprising a data bit set to indicate whether the print cartridge is either new or remanufactured. 
     According to at least one embodiment, the number of data bits set to indicate that the print cartridge is remanufactured corresponds to the number of times the print cartridge was remanufactured. 
     According to at least one embodiment, the second data comprises one or more second data fields, each data field corresponding to an instance of cartridge remanufacture and comprising one or more data bits that indicate print yield for the instance of cartridge remanufacture. 
     According to at least one embodiment, the print yield corresponds to the maximum number of pages that can be printed using the print cartridge. 
     According to at least one embodiment, the print yield corresponds to the maximum amount of fluid that can be ejected from the print cartridge. 
     According to at least one embodiment, the print yield corresponds to the maximum number of drop counts of fluid ejected from the print cartridge. 
     Other features and advantages of embodiments of the invention will become readily apparent from the following detailed description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of exemplary embodiments of the present invention will be more fully understood with reference to the following, detailed description when taken in conjunction with the accompanying figures, wherein: 
         FIG. 1  is a perspective view of an inkjet printhead according to an exemplary embodiment of the present invention; 
         FIG. 2  is a perspective view of an inkjet printer according to an exemplary embodiment of the present invention; and 
         FIG. 3  is a flowchart illustrating a method of determining the yield of a print cartridge upon installation into a printer according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the words “may” and “can” are used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. 
     With reference to  FIG. 1 , an inkjet printhead according to an exemplary embodiment of the present invention is shown generally as  10 . The printhead  10  has a housing  12  formed of any suitable material for holding ink. Its shape can vary and often depends upon the external device that carries or contains the printhead. The housing has at least one compartment  16  internal thereto for holding an initial or refillable supply of ink. In one embodiment, the compartment has a single chamber and holds a supply of black ink, photo ink, cyan ink, magenta ink or yellow ink. In other embodiments, the compartment has multiple chambers and contains three supplies of ink. Preferably, it includes cyan, magenta and yellow ink. In still other embodiments, the compartment contains plurals of black, photo, cyan, magenta or yellow ink. It will be appreciated, however, that while the compartment  16  is shown as locally integrated within a housing  12  of the printhead, it may alternatively connect to a remote source of ink and receive supply from a tube, for example. 
     Adhered to one surface  18  of the housing  12  is a portion  19  of a flexible circuit, especially a tape automated bond (TAB) circuit  20 . The other portion  21  of the TAB circuit  20  is adhered to another surface  22  of the housing. In this embodiment, the two surfaces  18 ,  22  are perpendicularly arranged to one another about an edge  23  of the housing. 
     The TAB circuit  20  supports a plurality of input/output (I/O) connectors  24  thereon for electrically connecting a heater chip  25  to an external device, such as a printer, fax machine, copier, photo-printer, plotter, all-in-one, etc., during use. Pluralities of electrical conductors  26  exist on the TAB circuit  20  to electrically connect and short the I/O connectors  24  to the input terminals (bond pads  28 ) of the heater chip  25 . Those skilled in the art know various techniques for facilitating such connections. For simplicity,  FIG. 1  only shows eight I/O connectors  24 , eight electrical conductors  26  and eight bond pads  28  but present day printheads have much larger quantities and any number is equally embraced herein. Still further, those skilled in the art should appreciate that while such number of connectors, conductors and bond pads equal one another, actual printheads may have unequal numbers. 
     The heater chip  25  contains a column  34  of a plurality of fluid firing elements that serve to eject ink from compartment  16  during use. The fluid firing elements may embody thermally resistive heater elements (heaters for short) formed as thin film layers on a silicon substrate or piezoelectric elements despite the thermal technology implication derived from the name heater chip. For simplicity, the pluralities of fluid firing elements in column  34  are shown adjacent an ink via  32  as a row of five dots but in practice may include several hundred or thousand fluid firing elements. As described below, vertically adjacent ones of the fluid firing elements may or may not have a lateral spacing gap or stagger there between. In general, the fluid firing elements have vertical pitch spacing comparable to the dots-per-inch resolution of an attendant printer. Some examples include spacing of 1/300 th , 1/600 th , 1/1200 th , 1/2400 th  or other of an inch along the longitudinal extent of the via. To form the vias, many processes are known that cut or etch the via  32  through a thickness of the heater chip. Some of the more preferred processes include grit blasting or etching, such as wet, dry, reactive-ion-etching, deep reactive-ion-etching, or other. A nozzle plate (not shown) has orifices thereof aligned with each of the heaters to project the ink during use. The nozzle plate may attach with an adhesive or epoxy or may be fabricated as a thin-film layer. 
     A memory unit  27  stores data related to information such as, for example, the production date, the lifetime and the number of refilled times that can be made. 
     With reference to  FIG. 2 , an external device in the form of an inkjet printer for containing the printhead  10  is shown generally as  40 . The printer  40  includes a carriage  42  having a plurality of slots  44  for containing one or more printheads  10 . The carriage  42  reciprocates (in accordance with an output  59  of a controller  57 ) along a shaft  48  above a print zone  46  by a motive force supplied to a drive belt  50  as is well known in the art. The reciprocation of the carriage  42  occurs relative to a print medium, such as a sheet of paper  52  that advances in the printer  40  along a paper path from an input tray  54 , through the print zone  46 , to an output tray  56 . 
     While in the print zone, the carriage  42  reciprocates in the Reciprocating Direction generally perpendicularly to the paper  52  being advanced in the Advance Direction as shown by the arrows. Ink drops from compartment  16  ( FIG. 1 ) are caused to be eject from the heater chip  25  at such times pursuant to commands of a printer microprocessor or other controller  57 . The timing of the ink drop emissions corresponds to a pattern of pixels of the image being printed. Often times, such patterns become generated in devices electrically connected to the controller  57  (via Ext. input) that reside externally to the printer and include, but are not limited to, a computer, a scanner, a camera, a visual display unit, a personal data assistant, or other. 
     To print or emit a single drop of ink, the fluid firing elements (the dots of column  34 ,  FIG. 1 ) are uniquely addressed with a small amount of current to rapidly heat a small volume of ink. This causes the ink to vaporize in a local ink chamber between the heater and the nozzle plate and eject through, and become projected by, the nozzle plate towards the print medium. The fire pulse required to emit such ink drop may embody a single or a split firing pulse and is received at the heater chip on an input terminal (e.g., bond pad  28 ) from connections between the bond pad  28 , the electrical conductors  26 , the I/O connectors  24  and controller  57 . Internal heater chip wiring conveys the fire pulse from the input terminal to one or many of the fluid firing elements. 
     A control panel  58 , having user selection interface  60 , also accompanies many printers as an input  62  to the controller  57  to provide additional printer capabilities and robustness. 
     Since the ink filled into a remanufactured cartridge is not necessarily equivalent to the ink filled originally, a printer will be unable to determine certain information for the remanufactured cartridge based on the information originally programmed into the cartridge memory. Such information may include, for example, how much ink is remaining in the cartridge, which in turn can be used to indicate when a new cartridge should be purchased or shipped to the customer, or to disable function of the cartridge when a certain amount of ink has been used (i.e., if cartridge is empty). 
     Exemplary embodiments of the present invention provide such information by including multiple fields in the memory unit  27  so that the printer can determine the ink remaining in the original cartridge as well as the same cartridge after it has been remanufactured. 
     For example, Table 1 below summarizes one possible implementation of the present invention. Each field has a specified number of bits reserved in the memory on the cartridge, with each bit representing a number of pages. The number of fields may correspond to the maximum number of times the printhead can be used. For example, the presence of three fields indicates that the cartridge can be remanufactured only twice. If N is the number of bits, and 50 page increments are desired, the maximum number of pages may be calculated as follows:
 
Total No. of Pages=2 N *50  (1)
 
     In alternative exemplary embodiments, each bit may represent other variables, such as, for example, grams of ink, or drop counts related to the ink filled. 
     
       
         
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Number 
                 Max at 50 
                   
               
               
                 Field Name 
                 of bits 
                 pages/bit 
                 Field Description 
               
               
                   
               
             
             
               
                 Original 
                 4 
                 800 
                 The number of pages provided by the 
               
               
                 Yield 
                   
                   
                 original production of the cartridge, 
               
               
                   
                   
                   
                 using the original ink fill amount. 
               
               
                   
                   
                   
                 This is programmed at the time of 
               
               
                   
                   
                   
                 original manufacture. 
               
               
                 Reman 1 
                 4 
                 800 
                 The number of pages that this 
               
               
                 Yield 
                   
                   
                 cartridge will provide after 
               
               
                   
                   
                   
                 the 1 st  reman operation. 
               
               
                   
                   
                   
                 This field is programmed at the 
               
               
                   
                   
                   
                 time of 1 st  remanufacture. 
               
               
                 Reman 2 
                 4 
                 800 
                 The number of pages that this 
               
               
                 Yield 
                   
                   
                 cartridge will provide after 
               
               
                   
                   
                   
                 the 2 nd  reman operation. 
               
               
                   
                   
                   
                 This field is programmed at the 
               
               
                   
                   
                   
                 time of 2 nd  remanufacture. 
               
               
                   
               
             
          
         
       
     
     The information of remanufactured yield could be used in conjunction with fields that indicate if the cartridge is new or used, or if it has been remanufactured. For example, if 3 bits are allocated to indicate a cartridge has been used (i.e., New/Used 1, New/Used 2, New/Used 3), each bit corresponding to an event of a cartridge install into a printer, the printer may use this information to determine which yield bits to use. For example, if all bits indicate New, then the cartridge is new, and the printer should use the field for Original Yield (and then set the New/Used 1 bit to indicate Used). If New/Used 1 indicates Used at install and the others indicate New, the cartridge was used once and remanufactured, so the printer should look at the Reman 1 Yield bits to obtain information on the amount of ink filled in the cartridge. If a more secure remanufacturing operation is required, additional fields may also be used to determine which Yield bits to use. Table 2 summarizes a possible implementation of this procedure: 
     
       
         
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 New/Used 
                 New/Used 
                 New/Used 
                   
               
               
                 1 
                 2 
                 3 
                 State 
               
               
                   
               
             
             
               
                 0 
                 0 
                 0 
                 Cartridge is new, use Original 
               
               
                   
                   
                   
                 Yield 
               
               
                 1 
                 0 
                 0 
                 Cartridge used once, reman once, 
               
               
                   
                   
                   
                 use Reman 1 Yield 
               
               
                 1 
                 1 
                 0 
                 Cartridge used twice, reman twice, 
               
               
                   
                   
                   
                 use Reman 2 Yield 
               
               
                 1 
                 1 
                 1 
                 Cartridge used 3 times, no more 
               
               
                   
                   
                   
                 reman allowed 
               
               
                   
               
               
                 All other cases are invalid 
               
             
          
         
       
     
       FIG. 3  is a flowchart illustrating a method of determining the yield of a print cartridge upon installation into a printer according to an exemplary embodiment of the present invention. The method begins at Step S 02 , where X is set equal to zero. At step S 04 , it is determined whether the first New/Used Bit is set to “1” (used) or “0” (new). If the first New/Used Bit is set to “0”, then the method proceeds to Step S 06 , where the original yield is calculated. In this step, the original yield is determined by referencing the number of bits in the original yield field (Table 1) and using Equation 1. The process then ends at Step S 08 . 
     If it is determined in Step S 04  that the first New/Used Bit is set equal to “1” (used), the method proceeds to step S 10 , where X is set equal to X+1. Next, in Step S 12 , it is determined whether the next New/Used Bit is set to “1” (used) or “0” (new). If the next New/Used Bit is set to “1”, the method returns to Step S 10 , where X is again set equal to X+1. 
     If it is determined in Step S 12  that the next New/Used Bit is set to “0”, the method proceeds to Step S 14 , where the field corresponding to the “X” number of bits set to “1” is determined (Table 2). Then, in Step S 16 , the yield of the remanufactured cartridge is determined based on the number of bits in the determined field (Table 1) and Equation 1. The process then ends at Step S 08 . 
     While particular embodiments of the invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.