Abstract:
A method may include the steps of providing a printing assembly that includes a plurality of printing modules that each include a specific toner color, wherein a first printing module is failing and at least one second printing module is functioning; determining a toner use demand for the plurality of printing modules; and swapping the first printing module with the at least one second printing module to facilitate reducing a downtime of the printing apparatus, wherein the first printing module has a toner use demand that is substantially greater than the toner use demand of the at least one second printing module.

Description:
FIELD OF THE INVENTION 
     This invention relates in general to electrographic printing, and more particularly to print on paper or transparency interchangeable multi-toner printing apparatus. 
     BACKGROUND OF THE INVENTION 
     One method for printing images on a receiver member is referred to as electrophotography. In one example, an electrophotographic printing device may create multi-color toner images using a plurality of color imaging printing modules coupled within the printing device. The printing modules may be arranged in tandem such that the toner images are successively electrostatically transferred to the receiver member. 
     Known examples of printing devices may deposit toner at specific locations on the receiver member and/or on top of other previously deposited toner using the plurality of printing modules. Once the receiver member has received the appropriate toner images the final print image may be permanently fixed to the receiver member typically using heat, and/or pressure. Multiple layers or marking materials can be overlaid on one receiver, for example, layers of different color particles can be overlaid on one receiver member to form a multi-color print image on the receiver member after fixing. 
     Many printing jobs such as in packaging require printing using interchangeable substrates or imaging modules. The present invention offers these options in an efficient and cost-efficient manner. 
     SUMMARY OF THE INVENTION 
     A method for increasing color interchangeability of 2 or more imaging modules, for example, the use of a white dry ink toner in either the first position of color laydown or the final position of color laydown so that similar looks can be obtained on different types of receivers, such as both transparent transparencies and opaque sheet paper. Another embodiment uses the white dry ink toner in either the first or last imaging position allows a dry ink module to be used for printing on colored substrate where the white dry ink toner is typically applied next to the paper (first), but underneath all the subsequent colors. Alternatively that same dry ink module to be used for printing on transparent substrates where the C, M, Y, K dry ink toners are typically applied next to the paper and the white is applied farthest from the clear substrate (last). 
     The invention, and its objects and advantages, will become more apparent in the detailed description of the exemplary embodiments described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which: 
         FIG. 1   a  is a schematic cross-sectional side view of an electrographic reproduction apparatus suitable for use with this invention; 
         FIG. 1   b  is a schematic cross-sectional side view of the electrographic reproduction apparatus shown in  FIG. 1   a;    
         FIG. 2   a  is a schematic cross-sectional side view of another embodiment of an electrographic reproduction apparatus; 
         FIG. 2   b  is a schematic cross-sectional side view of the electrographic reproduction apparatus shown in  FIG. 2   a;    
         FIG. 3  is an enlarged schematic cross-sectional side view of one printing module; and 
         FIG. 4  is a schematic cross-sectional side view of another embodiment of an electrographic reproduction apparatus. 
         FIG. 5  is a schematic cross section of another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the accompanying drawings,  FIGS. 1-4  show portions of an electrographic print engine or printer apparatus suitable for printing multi-color toner images. In one embodiment, as shown in  FIGS. 1   a  and  1   b , the printing apparatus may have four single-color image printing stations or modules arranged in tandem. In another embodiment, as shown in  FIGS. 2   a  and  2   b , the printing apparatus may have five image printing modules arranged in tandem. It is understood that the actual number of printing modules can be varied depending on the printer system employed. The invention contemplates that a plurality of printing modules may be combined to deposit toner on a single receiver member to produce multi-colored images. 
     This invention enables the customer to perform multiple imaging applications by altering which colors are printed in which imaging position in a multicolor printing system. The invention enables color interchangeability and takes advantage of that interchangeability to allow the same hardware and control system to be able to perform two applications. This allows a 5-color or “m-color” printer to perform the printing of a m+1 printer so that what previously would have required either a 6 color capable imaging system or multiple imaging systems now can be printed by a 5 color printer system. Both the colored substrate application and the transparent substrate application can now be performed on a 5 color capable imaging system. 
       FIGS. 1   a  and  1   b  are side elevation views of an electrographic printing apparatus  100 . In such an embodiment, printing apparatus  100  may include four printing modules, generally indicated as M 1 , M 2 , M 3  and M 4 . Printing modules M 1 -M 4  may be arranged in tandem and coupled within printing apparatus  100 . Each of printing modules M 1 -M 4  may generate a single-color toner image and may facilitate transferring that image to a receiver member  110  that may be successively moved through printing modules M 1 -M 4 . It should be understood that printing apparatus  100  is not limited to this tandem orientation or any other orientation. In the exemplary embodiment, printing module M 1  may form black (K) toner color separation images, printing module M 2  may form yellow (Y) toner color separation images, printing module M 3  may form magenta (M) toner color separation images, and printing module M 4  may form cyan (C) toner color separation images. 
     In one embodiment, printing modules M 1 -M 4  may be rotatably coupled to a transport device, such as endless belt web  112 . A plurality of receiver members  110  may be coupled to belt web  112 , wherein each receiver member  110  may receive the print image. Receiver members  110  may be removably electrostatically coupled to belt web  112  via corona tack-down chargers (not shown) or by mechanical devices such as grippers (not shown). 
       FIGS. 2   a  and  2   b  are side elevation views of an alternative printing apparatus  200  also referred to as a printing assembly. Components of printing apparatus  200  are substantially similar to components of printing apparatus  100  and therefore like components are identified with like reference numerals. Printing apparatus  200  may include printing modules M 1 , M 2 , M 3  and M 4 . Moreover, printing apparatus  200  may also include a fifth printing module M 5  that may include any fifth color, a clear toner or any of the four colors black (K), yellow (Y), magenta (M) or cyan (C) that may be contained within printing modules M 1 -M 4  as described above. In one embodiment, printing modules M 1 -M 5  may be arranged in tandem and coupled within printing apparatus  200 . In another embodiment, printing modules M 1 -M 5  may be arranged in any other orientation. 
     Similarly, as described above, in one embodiment, printing modules M 1 -M 5  may be rotatably coupled to belt web  112 . The plurality of receiver members  110  may be coupled to belt web  112 , wherein each receiver member  110  may receive the print image. Receiver members  110  may be removably electrostatically coupled to belt web  112  via the corona tack-down chargers or the grippers. 
       FIG. 3  is an enlarged side view of printing module M 1 . It should be understood that each of the printing modules M 1 -M 5  are substantially identical. As a result, the following description of printing module M 1  may apply to printing modules M 2 -M 5 . In the exemplary embodiment, printing module M 1  may include a photoconductive imaging roller  114  and a transfer backup roller  116 . Photoconductive imaging roller  114  may have a surface  118  that may be rotatably coupled to belt web  112 . Transfer backup roller  116  may also be rotatably coupled to belt web  112  such that transfer backup roller  116  may be positioned substantially adjacent to photoconductive imaging roller  114  such that a transfer nip  120  may be defined therebetween. 
     Printing module M 1  may also include a plurality of electrographic imaging subsystems for producing one or more multilayered images or patterns. For example, in one embodiment, printing module M 1  may include a cleaner system  122  that may be operatively coupled to surface  118 . Printing module M 1  may also include a primary charging system  124  that is operatively coupled to surface  118  of photoconductive imaging roller  114 , wherein primary charging system  124  may facilitate uniformly electrostatically charging surface  118 . Moreover, printing module M 1  may include an exposure subsystem  126  that may be operatively coupled to surface  118 , wherein exposure subsystem  126  may facilitate image-wise modulating the uniform electrostatic charge by exposing photoconductive imaging roller  114  to form a latent electrostatic multi-layer (separation) image of the respective layers. Printing module M 1  may also include a dry ink, or toner station  128  that may be operatively coupled to surface  118 , wherein toner station  128  may facilitate depositing a color toner image  130  on surface  118  of photoconductive imaging roller  114 . 
     A logic control unit (LCU)  132  may be provided and may include a microprocessor incorporating suitable look-up tables and control software, which may be executable by LCU  132 . The control software may be stored in a memory associated with LCU  132 . The control software may include image processing algorithms that facilitate sending the correct image data, or plane, to the appropriate printing module. Moreover, each printing module M 1 -M 5  may have unique calibrations that are color specific and/or module specific. In one embodiment, LCU  132  may facilitate reassigning the unique calibrations to another printing module, as described in more detail below. In another embodiment, LCU  132  may facilitate repeating, or copying, the unique calibrations for a specific color to a different printing module, as described in more detail below. Each toner station  128  may include a toner color identifier (not shown) that may be detected by a plurality of sensors (not shown) coupled within printing modules M 1 -M 5 . In a non-limiting example, LCU  132  may automatically reprogram printing module M 1  in response to the sensors in the event toner station  128  is swapped out of one of the other printing modules M 2 -M 5  and coupled within printing module M 1 . Furthermore, LCU  132  may generally nominalize and/or optimize the operating parameters and reduce errors which are attributable to the printing process. 
     A power supply unit  134  may provide individual transfer currents to the transfer backup rollers  116 . LCU  132  may provide control of the various components and process control parameters of the apparatus in response to signals from various sensors (not shown) associated with the electrophotographic printer apparatus. LCU  132  may also provide timing and control signals to the respective components to provide control of the printing apparatus in accordance with well understood and known. 
     During operation, receiver members  110  may be channeled from a paper supply unit (not shown) and transported through the printing modules M 1 -M 5  in a direction as indicated in  FIG. 3 . Receiver members  110  may be coupled to belt web  112  electrostatically coupled via the corona tack-down chargers. As a result, receiver member  110  may be channeled from the supply source towards transfer nip  120  of printing module M 1 . In the exemplary embodiment, a colored toner image may be created on surface  118  by exposure subsystem  126 , charging system  124  and toner station  128 . Photoconductive imaging roller  114  may transfer the respective toner layer (separation) image to receiver member  110 . As a result, an unfused toner image  130  may be formed on receiver member  110  shown in  FIG. 3  as exiting transfer nip  120 . Receiver member  110  may then be channeled towards printing modules M 2 -M 5  wherein receiver member  110  may receive additional toner images coupled thereon. Finally, receiver member  110  may be channeled to a finishing assembly (not shown) that facilitates fusing toner image  130  to receiver member  110 . 
     This invention enables the customer to perform multiple imaging applications by altering which colors are printed in which imaging position in a multicolor printing system having multiple printer modes as shown in  FIG. 3 . The invention enables color interchangeability and takes advantage of the interchangeability to allow the same hardware and control system to be able to perform two or more applications. This allows a 5 color or m color printer, as shown in  FIG. 3 , to perform the printing of a m+1 printer so that what previously would have required either a 6 color capable imaging system or more now can be printed by a 5 color (m) printer system. In the exemplary embodiment, printing module M 1  may deposit black (K) toner color separation images; printing module M 2  may deposit yellow (Y) toner color separation images; printing module M 3  may deposit magenta (M) toner color separation images; and printing module M 4  may deposit cyan (C) toner color separation images. An optional printing module M 5 , as shown in printing assembly  200  in  FIGS. 2   a  and  2   b , may form colors such as red, blue, green or any other color separation image, a clear toner, a gloss finish or type of film. 
     One embodiment of the printing apparatus also referred to as an interchangeable printer  300  is shown in  FIG. 4 , having a fifth printing module M 5 . The printer is capable of printing using one or more colors such as Black (K) of the colors, Yellow (Y), Magenta (M) and Cyan (C) using printing modules M 1 -M 4 , respectively. The printing apparatus  300  has components like those described above for the printer or printing apparatus  200 . In one embodiment where white is needed the printing module M 5  also can print a black K-colored toner, or any color that has a high demand and a known substrate type to be printed on. The substrate type then determines which of the color modules will print and in what order. This embodiment does not need the printer to automatically adjust the placement of the modules since the operator does this manually prior to printing as shown in  FIG. 4 . In this example the white toner module is first to print for a colored substrate and is changed to the last to print with a transparent substrate resulting in the same look as on the other paper. 
     Another embodiment is shown in  FIG. 5  is an automatic embodiment where a 6 color capable printing system has white in, both the first and last (sixth) imaging module locations, thereby eliminating any need to manually interchange modules, and still accomplish the required laydown order on various substrate types such as the colored substrate and the transparent substrate used the same imaging system without operator intervention. 
     In the embodiment shown in  FIG. 5  the printer automatically determines a substrate type by various methods of detection such as a densitometer, or any optical sensors that detects light transmittability and/or reflectivity. Substrate types can be classified by various measurements such as surface charactures, color hue of substrate in relation to the surface, printed indicia and other relevant substrate characters. 
     This embodiment is an exemplary non-limiting example of color interchangeability of the imaging modules enables the use of a white dry ink toner in either the first position of color laydown or the final position of color laydown. This means of increasing color interchangeability of imaging modules could actually apply to any color or set of colors but the example of white shows how effective this can be in different circumstances. For example the ability to have white dry ink toner in either the first or last imaging position allows a dry ink module to be used for printing on colored substrate where the white dry ink toner is typically applied next to the paper (first), but underneath all the subsequent colors. Alternatively that same dry ink module to be used for printing on transparent substrates where the C, M, Y, K dry ink toners are typically applied next to the paper and the white is applied farthest from the clear substrate (last). When the white is printed as the first layer of toner on the paper substrate it can be used for printing on colored substrates and preserves the color integrity of the other colors placed on top of it. This means it acts like a white paper backing on the colored papers. When the white is printed as the last layer of toner ink on clear substrate, appears as white wherever white is needed as a reverse image as for a backlit display or a packaging label. 
     This method for functionally interchanging printing modules during printing for this invention uses the steps of providing a printing assembly ( 400 ) that includes a plurality of printing modules (M 1 -M 4 ) that each include a specific toner color, wherein a first printing module (M 1 ) assigned a toner, such as a white toner, prints the first color (white) toner. The second printing module (M 2 ) prints a second color toner and a controller controls the first printing module (M 1 ) in relation to the at least one second printing module (M 2 ) to facilitate an adjustment of the printing apparatus ( 100 ), wherein the first printing module (M 1 ) has a white toner use demand or it is predetermined that the white toner is a substantially better fit to the receiver and image. 
     This invention can be used in conjunction with U.S. Ser. No. 12/330,772, filed Dec. 9, 2008 to detect and correct for module which is hereby incorporated by reference. 
     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 PARTS LIST 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Printing apparatus 
                 100 
               
               
                   
                 Receiver member 
                 110 
               
               
                   
                 Belt web 
                 112 
               
               
                   
                 Photoconductive imaging roller 
                 114 
               
               
                   
                 Transfer backup roller 
                 116 
               
               
                   
                 Surface 
                 118 
               
               
                   
                 Cleaner system 
                 122 
               
               
                   
                 Charging system 
                 124 
               
               
                   
                 Exposure subsystem 
                 126 
               
               
                   
                 Toner station 
                 128 
               
               
                   
                 Color toner image 
                 130 
               
               
                   
                 Logic control unit 
                 132 
               
               
                   
                 Power supply unit 
                 134 
               
               
                   
                 Printing assembly 
                 200 
               
               
                   
                 Interchangeable printer or printing apparatus  
                 300