Abstract:
An inkjet printing system includes an electronic controller including electronics providing first signals having first signaling levels, and low voltage differential signaling (LVDS) drivers which receive the first signals and convert the first signals to second signals having LVDS levels. Cabling is coupled to the LVDS drivers and carries the second signals to an inkjet printhead assembly. The inkjet printhead assembly includes LVDS receivers coupled to the cabling and receiving the second signals and converting the second signals to third signals having third signaling levels.

Description:
This is a Continuation of application Ser. No. 09/779,281 filed Feb. 8, 2001. 
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Non-Provisional Patent Application is related to commonly-assigned U.S. Patent Application “MODULE MANAGER FOR WIDE-ARRAY INKJET PRINTHEAD ASSEMBLY” filed on Jan. 5, 2001, with Attorney Docket No. 10002118-1, which is herein incorporated by reference. 
    
    
     THE FIELD OF THE INVENTION 
     The present invention relates generally to inkjet printheads, and more particularly to communicating signals to an inkjet printhead assembly with low voltage differential signaling. 
     BACKGROUND OF THE INVENTION 
     A conventional inkjet printing system includes a printhead, an ink supply which supplies liquid ink to the printhead, and an electronic controller which controls the printhead. The printhead ejects ink drops through a plurality of orifices or nozzles and toward a print medium, such as a sheet of paper, so as to print onto the print medium. Typically, the orifices are arranged in one or more arrays such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead and the print medium are moved relative to each other. 
     Typically, the printhead ejects the ink drops through the nozzles by rapidly heating a small volume of ink located in vaporization chambers with small electric heaters, such as thin film resisters. Heating the ink causes the ink to vaporize and be ejected from the nozzles. Typically, for one dot of ink, a remote printhead controller typically located as part of the processing electronics of a printer, controls activation of an electrical current from a power supply external to the printhead. The electrical current is passed through a selected thin film resister to heat the ink in a corresponding selected vaporization chamber. 
     Advanced printhead designs now permit an increased number of nozzles to be implemented on a single printhead. Moreover, in one arrangement, commonly referred to as a wide-array inkjet printing system, a plurality of individual printheads, also referred to as printhead dies, are mounted on a single carrier. In these arrangements, a number of nozzles and, therefore, an overall number of ink drops which can be ejected per second is increased. Since the overall number of drops which can be ejected per second is increased, printing speed can be increased with a wide-array inkjet printing system and/or printheads having an increased number of nozzles. 
     As the number of nozzles on a single carrier or a single printhead increases, the number of corresponding thin film resisters which need to be electrically coupled to the remote printhead controller correspondingly increases, which results in a correspondingly large number of conductive paths carrying nozzle data, fire signals, and other data signals to the printheads. Voltage switching in the large number of signals carried on the conductive paths generates undesirable electromagnetic interference (EMI). In addition, the ejection of ink from the nozzles (i.e., firing of the nozzles) requires a switching on and off of a large amount of electrical current in a short amount of time. The switching on and off of nozzle current of a large number of nozzles simultaneously generates undesirable EMI. 
     The EMI generated as a result of voltage switching in the signals carried on the conductive paths and nozzle firing causes conductive paths, such as cables, to conduct and/or radiate undesirable EMI. EMI is undesirable because EMI interferes with internal components of the printing system and can also interfere with other electric devices and appliances not associated with the printing system, such as computers, radios, and televisions. Moreover, systems, such as printing systems, typically need to comply to an electromagnetic compliance (EMC) standard which defines limits to levels of stray EMI noise signals. For example, EMC standards are set by government regulatory agencies, such as the Federal Communications Commission (FCC), which set electrical emission standards for electric devices. 
     For reasons stated above and for other reasons presented in greater detail in the Description of the Preferred Embodiment section of the present specification, an inkjet printing system is desired which minimizes the amount of undesirable EMI conducted and/or radiated by the conductive paths which communicate data signals from the electronic controller to the printhead(s). 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention provides an inkjet printing system including an electronic controller and inkjet printhead assembly coupled together via cabling. The electronic controller includes electronics providing first signals having first signaling levels. The electronic controller also includes low voltage differential signaling (LVDS) drivers which receive the first signals and convert the first signals to second signals having LVDS levels. The cabling is coupled to the LVDS drivers and carries the second signals to the inkjet printhead assembly. The inkjet printhead assembly includes LVDS receivers coupled to the cabling and receiving the second signals and converting the second signals to third signals having third signaling levels. 
     One aspect of the present invention provides an electronic controller for an inkjet printing system. The electronic controller is adapted to couple to cabling. The cabling is coupled to an inkjet printhead assembly in the inkjet printing system. The electronic controller includes electronics which provide first signals having first signaling levels. The electronic controller includes LVDS drivers which receive the first signals, convert the first signals to second signals having LVDS levels, and provide the second signals to the cabling. 
     One aspect of the present invention provides a method of inkjet printing including providing first signals having first signaling levels in an electronic controller. The method includes converting the first signals to second signals having LVDS levels in the electronic controller. The method includes carrying the second signals to an inkjet printhead assembly. The method includes receiving the second signals in the inkjet printhead assembly. The method includes converting the second signals to third signals having third signaling levels in the inkjet printhead assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram illustrating one embodiment of an inkjet printing system. 
     FIG. 2 is a diagram of one embodiment of an inkjet et printhead sub-assembly or module. 
     FIG. 3 is an enlarged schematic cross-sectional view illustrating portions of a one embodiment of a printhead die in the printing system of FIG.  1 . 
     FIG. 4 is a block diagram illustrating one embodiment of an inkjet printing system according to the present invention which employs low voltage differential signaling (LVDS) to communicate data to a printhead. 
     FIG. 5 is a block diagram illustrating one embodiment of an inkjet printing system according to the present invention employing LVDS to communicate data between an electronic controller and a printhead. 
     FIG. 6 is a block diagram illustrating a portion of an inkjet printhead assembly having a module manager integrated circuit (IC). 
     FIG. 7 is a block diagram illustrating an inkjet printing system according to the present invention employing LVDS to communicate data to a printhead assembly having a module manager IC. 
     FIG. 8 is a block diagram of an inkjet printing system according to the present invention employing LVDS to communicate data between an electronic controller and a printhead assembly having a module manager IC. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. The inkjet printhead assembly and related components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. 
     FIG. 1 illustrates one embodiment of an inkjet printing system  10 . Inkjet printing system  10  includes an inkjet printhead assembly  12 , an ink supply assembly  14 , a mounting assembly  16 , a media transport assembly  18 , and an electronic controller  20 . At least one power supply  22  provides power to the various electrical components of inkjet printing system  10 . Inkjet printhead assembly  12  includes at least one printhead or printhead die  40  which ejects drops of ink through a plurality of orifices or nozzles  13  and toward a print medium  19  so as to print onto print medium  19 . Print medium  19  is any type of suitable sheet material, such as paper, card stock, transparencies, Mylar, and the like. Typically, nozzles  13  are arranged in one or more columns or arrays such that properly sequenced ejection of ink from nozzles  13  causes characters, symbols, and/or other graphics or images to be printed upon print medium  19  as inkjet printhead assembly  12  and print medium  19  are moved relative to each other. 
     Ink supply assembly  14  supplies ink to printhead assembly  12  and includes a reservoir  15  for storing ink. As such, ink flows from reservoir  15  to inkjet printhead assembly  12 . Ink supply assembly  14  and inkjet printhead assembly  12  can form either a one-way ink delivery system or a recirculating ink delivery system. In a one-way ink delivery system, substantially all of the ink supplied to inkjet printhead assembly  12  is consumed during printing. In a recirculating ink delivery system, however, only a portion of the ink supplied to printhead assembly  12  is consumed during printing. As such, ink not consumed during printing is returned to ink supply assembly  14 . 
     In one embodiment, inkjet printhead assembly  12  and ink supply assembly  14  are housed together in an inkjet cartridge or pen. In another embodiment, ink supply assembly  14  is separate from inkjet printhead assembly  12  and supplies ink to inkjet printhead assembly  12  through an interface connection, such as a supply tube. In either embodiment, reservoir  15  of ink supply assembly  14  may be removed, replaced, and/or refilled. In one embodiment, where inkjet printhead assembly  12  and ink supply assembly  14  are housed together in an inkjet cartridge, reservoir  15  includes a local reservoir located within the cartridge as well as a larger reservoir located separately from the cartridge. As such, the separate, larger reservoir serves to refill the local reservoir. Accordingly, the separate, larger reservoir and/or the local reservoir may be removed, replaced, and/or refilled. 
     Mounting assembly  16  positions inkjet printhead assembly  12  relative to media transport assembly  18  and media transport assembly  18  positions print medium  19  relative to inkjet printhead assembly  12 . Thus, a print zone  17  is defined adjacent to nozzles  13  in an area between inkjet printhead assembly  12  and print medium  19 . In one embodiment, inkjet printhead assembly  12  is a scanning type printhead assembly. As such, mounting assembly  16  includes a carriage for moving inkjet printhead assembly  12  relative to media transport assembly  18  to scan print medium  19 . In another embodiment, inkjet printhead assembly  12  is a non-scanning type printhead assembly. As such, mounting assembly  16  fixes inkjet printhead assembly  12  at a prescribed position relative to media transport assembly  18 . Thus, media transport assembly  18  positions print medium  19  relative to inkjet printhead assembly  12 . 
     Electronic controller or printer controller  20  typically includes a processor, firmware, and other printer electronics for communicating with and controlling inkjet printhead assembly  12 , mounting assembly  16 , and media transport assembly  18 . Electronic controller  20  receives data  21  from a host system, such as a computer, and includes memory for temporarily storing data  21 . Typically, data  21  is sent to inkjet printing system  10  along an electronic, infrared, optical, or other information transfer path. Data  21  represents, for example, a document and/or file to be printed. As such, data  21  forms a print job for inkjet printing system  10  and includes one or more print job commands and/or command parameters. 
     In one embodiment, the at least one printhead  40  in inkjet assembly  12  is directly coupled to electronic controller  20 . In this embodiment, electronic controller  20  controls inkjet printhead assembly  12  for ejection of ink drops from nozzles  13 . As such, electronic controller  20  defines a pattern of ejected ink drops which form characters, symbols, and/or other graphics or images on print medium  19 . The pattern of ejected ink drops is determined by the print job commands and/or command parameters. 
     In one embodiment, logic and drive circuitry are incorporated in a module manager integrated circuit (IC)  50  located on inkjet printhead assembly  12 . Module manager IC  50  is similar to the module manager IC discussed in the above incorporated commonly-assigned patent application entitled “MODULE MANAGER FOR WIDE-ARRAY INKJET PRINTHEAD ASSEMBLY.” In this embodiment, electronic controller  20  and module manager IC  50  operate together to control inkjet printhead assembly  12  for ejection of ink drops from nozzles  13 . As such, electronic controller  20  and module manager IC  50  define a pattern of ejected ink drops which form characters, symbols, and/or other graphics or images on print medium  19 . The pattern of ejected ink drops is determined by the print job commands and/or command parameters. 
     In one embodiment, inkjet printhead assembly  12  is a wide-array or multi-head printhead assembly. In one embodiment, inkjet printhead assembly  12  includes a carrier  30 , which carries printhead dies  40  and module manager IC  50 . In one embodiment carrier  30  provides electrical communication between printhead dies  40 , module manager IC  50 , and electronic controller  20 , and fluidic communication between printhead dies  40  and ink supply assembly  14 . 
     In one embodiment, printhead dies  40  are spaced apart and staggered such that printhead dies  40  in one row overlap at least one printhead die  40  in another row. Thus, inkjet printhead assembly  12  may span a nominal page width or a width shorter or longer than nominal page width. In one embodiment, a plurality of inkjet printhead sub-assemblies or modules  12 ′ (illustrated in FIG. 2) form one inkjet printhead assembly  12 . The inkjet printhead modules  12 ′ are substantially similar to the above described printhead assembly  12  and each have a carrier  30  which carries a plurality of printhead dies  40  and a module manager IC  50 . In one embodiment, the printhead assembly  12  is formed of multiple inkjet printhead modules  12 ′ which are mounted in an end-to-end manner and each carrier  30  has a staggered or stair-step profile. As a result, at least one printhead die  40  of one inkjet printhead module  12 ′ overlaps at least one printhead die  40  of an adjacent inkjet printhead module  12 ′. 
     A portion of one embodiment of a printhead die  40  is illustrated schematically in FIG.  3 . Printhead die  40  includes an array of printing or drop ejecting elements  42 . Printing elements  42  are formed on a substrate  44  which has an ink feed slot  441  formed therein. As such, ink feed slot  441  provides a supply of liquid ink to printing elements  42 . Each printing element  42  includes a thin-film structure  46 , an orifice layer  47 , and a firing resistor  48 . Thin-film structure  46  has an ink feed channel  461  formed therein which communicates with ink feed slot  441  of substrate  44 . Orifice layer  47  has a front face  471  and a nozzle opening  472  formed in front face  471 . Orifice layer  47  also has a nozzle chamber  473  formed therein which communicates with nozzle opening  472  and ink feed channel  461  of thin-film structure  46 . Firing resistor  48  is positioned within nozzle chamber  473  and includes leads  481  which electrically couple firing resistor  48  to a drive signal and ground. 
     During printing, ink flows from ink feed slot  441  to nozzle chamber  473  via ink feed channel  461 . Nozzle opening  472  is operatively associated with firing resistor  48  such that droplets of ink within nozzle chamber  473  are ejected through nozzle opening  472  (e.g., normal to the plane of firing resistor  48 ) and toward a print medium upon energization of firing resistor  48 . 
     Example embodiments of printhead dies  40  include a thermal printhead, a piezoelectric printhead, a flex-tensional printhead, or any other type of inkjet ejection device known in the art. In one embodiment, printhead dies  40  are fully integrated thermal inkjet printheads. As such, substrate  44  is formed, for example, of silicon, glass, or a stable polymer and thin-film structure  46  is formed by one or more passivation or insulation layers of silicon dioxide, silicon carbide, silicon nitride, tantalum, poly-silicon glass, or other suitable material. Thin-film structure  46  also includes a conductive layer which defines firing resistor  48  and leads  481 . The conductive layer is formed, for example, by aluminum, gold, tantalum, tantalum-aluminum, or other metal or metal alloy. 
     Printhead assembly  12  can include any suitable number (N) of printheads  40 , where N is at least one. Before a print operation can be performed, data must be sent to printhead  40  from electronic controller  20 . Data includes, for example, print data and non-print data for printhead  40 . Print data includes, for example, nozzle data containing pixel information, such as bitmap print data. Non-print data includes, for example, command/status (CS) data, clock data, and/or synchronization data. Status data of CS data includes, for example, printhead temperature or position, printhead resolution, and/or error notification. Example non-print data includes fire signals generated by electronic controller  20  remote from printhead  40  to control the timing and activation of an electrical current from power supply  22  to thereby control the ejection of ink drops from printhead  40 . In one embodiment, printheads  40  receive fire signals containing fire pulses from electronic controller  20 . 
     One embodiment of an inkjet printing system according to the present invention is illustrated generally at  110  in FIG.  4 . Inkjet printing system  110  includes an electronic controller  120  similar to electronic controller  20  of inkjet printing system  10 . Inkjet printing system  110  also includes a printhead  140  similar to printhead  40  described above. Inkjet printing system  110  employs low voltage differential signaling (LVDS) to communicate data from electronic controller  120  to printhead  140 . By contrast, conventional inkjet printing systems typically employ standard transistor-transistor logic (TTL) or complementary metal-oxide semiconductor (CMOS) signaling levels to communicate data to an inkjet printhead. 
     Electronic controller  120  includes LVDS drivers  100  which receive CMOS or TTL signaling level data on lines  102 . Electronic controller  120  includes electronics which provide the CMOS or TTL signaling level data on lines  102 . LVDS drivers  100  convert the CMOS or TTL signaling level data to LVDS levels. LVDS drivers  100  provide LVDS level data on cabling  104 . 
     Cabling  104  carries the LVDS level data to LVDS receivers  106  in printhead  140 . LVDS receivers  106  convert the LVDS level data carried on cabling  104  to CMOS or TTL signaling level data which is provided on lines  108 . Lines  108  are coupled to printhead electronics which utilize the CMOS or TTL signaling level data. 
     The data communicated from electronic controller  120  to printhead  140  via LVDS on cabling  104  can be print data or non-print data. In one embodiment, signals, other than data, transmitted from electronic controller  120  to printhead  140  employ LVDS drivers  100  in electronic controller  120  and LVDS receivers  106  in printhead  140  to provide LVDS communication from electronic controller  120  to printhead  140 . 
     The LVDS employed by inkjet printing system  110  to communicate data and possibly other signals from electronic controller  120  to printhead  140  over cabling  104  substantially reduces voltage swings in the signals carried on the cabling. LVDS, accordingly, substantially reduces the amount of electromagnetic interference (EMI) conducted and/or radiated by cabling  104 , as compared to the EMI conducted and/or radiated by the cabling in conventional inkjet printing systems which carries data and other signals from the electronic controller to the printhead using standard CMOS or TTL signaling. Moreover, high-speed signal integrity of signals communicated via cabling  104  is increased with LVDS, as compared to standard CMOS or TTL signaling. 
     An alternative embodiment inkjet printing system according to the present invention is generally illustrated at  210  in FIG.  5 . Inkjet printing system  210  includes an electronic controller  220  similar to electronic controller  120  of inkjet printing system  110 . Electronic controller  220  communicates with a printhead  240  similar to printhead  140  of inkjet printing system  110 . However, electronic controller  220  includes LVDS drivers and receivers  200  which communicate with lines  202 . Lines  202  carry CMOS or TTL signaling level data. LVDS drivers and receivers  200  also communicate with cabling  204 . Cabling  204  is coupled to and communicates with LVDS receivers and drivers  206  in printhead  240 . LVDS receivers and drivers  206  are coupled to and communicate with lines  208 . Lines  208  communicate CMOS or TTL signaling level data with electronics in printhead  240 . 
     In one operation, the LVDS drivers and receivers  200  convert CMOS or TTL signaling level data on lines  202  to LVDS level data which is provided on cabling  204  to LVDS receivers and drivers  206  in printhead  240 . The LVDS receivers and drivers  206  convert the LVDS data from cabling  204  to CMOS or TTL signaling level data provided on lines  208  to the electronics in printhead  240 . 
     In another operation, LVDS receivers and drivers  206  convert CMOS or TTL signaling level data or signals provided from electronics in printhead  240  on lines  208  to LVDS level data or signals provided on cabling  204 . Cabling  204  provides the LVDS level data or signals to LVDS drivers and receivers  200  in electronic controller  220 . LVDS drivers and receivers  200  receive the LVDS level data or signals and convert the LVDS level data or signals to corresponding CMOS or TTL signaling level data or signals, which are provided on lines  202  to electronics in electronic controller  220 . 
     For example, in one embodiment of inkjet printing system  210  illustrated in FIG. 5, status data read from printhead  240  is provided back to electronic controller  220  with LVDS. Therefore, any type of print data, non-print data, or other signaling can be communicated from electronic controller  220  to printhead  240  or from printhead  240  to electronic controller  220  employing LVDS on cabling  204 . In this way, any data or signals communicated between electronic controller  220  and printhead  240  employing LVDS have substantially reduced voltage swings in cabling  204 , as compared to CMOS or TTL signaling level voltage swings. The reduced voltage swings in cabling  204  correspondingly reduce the amount of EMI conducted and/or radiated by cabling  204 , as compared to conventional cabling between an electronic controller and printhead using standard CMOS or TTL signaling. 
     A portion of one embodiment of an inkjet printhead assembly  12  is illustrated generally in FIG.  6 . Inkjet printhead assembly  12  includes complex analog and digital electronic components. Thus, inkjet printhead assembly  12  includes printhead power supplies for providing power to the electronic components within printhead assembly  12 . For example, a Vpp power supply  52  and corresponding power ground  54  supply power to the firing resisters in printheads  40 . An example 5-volt analog power supply  56  and corresponding analog ground  58  supply power to the analog electronic components in printhead assembly  12 . An example 5-volt logic supply  60  and a corresponding logic ground  62  supply power to logic devices requiring a 5-volt logic power source. A 3.3-volt logic power supply  64  and the logic ground  62  supply power to logic components requiring a 3.3-volt logic power source, such as module manager  50 . In one embodiment, module manager  50  is an application specific integrated circuit (ASIC) requiring a 3.3-volt logic power source. 
     In the example embodiment illustrated in FIG. 6, printhead assembly  12  includes eight printheads  40 . Printhead assembly  12  can include any suitable number (N) of printheads. Before a print operation can be performed, data must be sent to printheads  40 . Data includes, for example, print data and non-print data for printheads  40 . Print data includes, for example, nozzle data containing pixel information, such as bitmap print data. Non-print data includes, for example, command/status (CS) data, clock data, and/or synchronization data. Status data of CS data includes, for example, printhead temperature or position, printhead resolution, and/or error notification. 
     Module manager IC  50  according to the present invention receives data from electronic controller  20  and provides both print data and non-print data to the printheads  40 . For each printing operation, electronic controller sends nozzle data to module manager IC  50  on a print data line  66  in a serial format. The nozzle data provided on print data line  66  may be divided into two or more sections, such as even and odd nozzle data. In the example embodiment illustrated in FIG. 6, serial print data is received on print data line  66  which is 6 bits wide. The print data line  66  can be any suitable number of bits wide. 
     Independent of nozzle data, command data from electronic controller  20  may be provided to and status data read from printhead assembly  12  over a serial bi-directional non-print data serial bus  68 . 
     A clock signal from electronic controller  20  is provided to module manager IC  50  on a clock line  70 . A busy signal is provided from module manager IC  50  to electronic controller  20  on a line  72 . 
     Module manager IC  50  receives the print data on line  66  and distributes the print data to the appropriate printhead  40  via data line  74 . In the example embodiment illustrated in FIG. 6, data line  74  is 32 bits wide to provide four bits of serial data to each of the eight printheads  40 . Data clock signals based on the input clock received on line  70  are provided on clock line  76  to clock the serial data from data line  74  into the printheads  40 . In the example embodiment illustrated in FIG. 6, clock line  76  is eight bits wide to provide clock signals to each of the eight printheads  40 . 
     Module manager IC  50  writes command data to and reads status data from printheads  40  over serial bi-directional CS data line  78 . A CS clock is provided on CS clock line  80  to clock the CS data from CS data line  78  to printheads  40  and to module manager  50 . 
     In the example embodiment of inkjet printhead assembly  12  illustrated in FIG. 6, the number of conductive paths in the print data interconnect between electronic controller  20  and inkjet printhead assembly  12  is significantly reduced, because an example module manager IC (e.g., ASIC)  50  is capable of much faster data rates than data rates provided by current printheads. For one example printhead design and example module manager ASIC  50  design, the print data interconnect is reduced from 32 pins to six lines to achieve the same printing speed, such as in the example embodiment of inkjet printhead assembly  12  illustrated in FIG.  6 . This reduction in the number of conductive paths in the print data interconnect significantly reduces costs and improves reliability of the printhead assembly and the printing system. 
     In addition, module manager IC  50  can provide certain functions that can be shared across all the printheads  40 . In this embodiment, the printhead  40  can be designed without certain functions, such as memory and/or processor intensive functions, which are instead performed in module manager IC  50 . In addition, functions performed by module manager IC  50  are more easily updated during testing, prototyping, and later product revisions than functions performed in printheads  40 . 
     Moreover, certain functions typically performed by electronic controller  20  can be incorporated into module manager IC  50 . For example, one embodiment of module manager IC  50  monitors the relative status of the multiple printheads  40  disposed on carrier  30 , and controls the printheads  40  relative to each other, which otherwise could only be monitored/controlled relative to each other off the carrier with the electronic controller  20 . 
     In one embodiment, module manager IC  50  permits standalone printheads to operate in a multi-printhead printhead assembly  12  without modification. A standalone printhead is a printhead which is capable of being independently coupled directly to an electronic controller. One example embodiment of printhead assembly  12  includes standalone printheads  40  which are directly coupled to module manager IC  50 . 
     One embodiment of an inkjet printing system according to the present invention which utilizes a module manager IC to communicate with multiple printheads is generally illustrated at  310  in FIG.  7 . Inkjet printing system  310  includes electronic controller  320  which is similar to electronic controller  120  of inkjet printing system  110 . Electronic controller  320  includes LVDS drivers  300  which receive CMOS or TTL signaling level data from lines  302 . Electronic controller  320  includes electronics which provide the CMOS or TTL signaling level data on lines  302 . LVDS drivers  300  convert the CMOS or TTL signaling level data to LVDS level data which is provided on cabling  304 . 
     Inkjet printing system  310  includes printhead assembly  312 . Printhead assembly  312  includes LVDS receivers  306  which are coupled to cabling  304 . LVDS receivers  306  convert the LVDS level data received on cabling  304  to CMOS signaling level data provided on line  308  to module manager IC  350  of printhead assembly  312 . Module manager IC  350  operates similar to module manager IC  50  described above in reference to FIG. 6 to communicate with multiple printheads  340 , which are similar to the multiple printheads  40  described above in reference to FIG.  6 . 
     The LVDS employed by inkjet printing system  310  to communicate data and possibly other signals from electronic controller  320  to printhead assembly  312  over cabling  304  substantially reduces voltage swings in the signals carried on the cabling. LVDS, accordingly, substantially reduces the amount of EMI conducted and/or radiated by cabling  304 , as compared to the EMI conducted and/or radiated by the cabling in conventional inkjet printing systems which carries data and other signals from the electronic controller to the printhead assembly using standard CMOS or TTL signaling. Furthermore, high-speed signal integrity of the signals carried on cabling  304  is increased with LVDS, as compared to standard CMOS or TTL signaling. 
     An alternative embodiment of an inkjet printing system according to the present invention which utilizes a module manager IC to communicate with multiple printheads is generally illustrated at  410  in FIG.  8 . Inkjet printing system  410  includes electronic controller  420  which is similar to electronic controller  220  of inkjet printing system  210 . Electronic controller  420  includes LVDS drivers and receivers  400  which, in one operation, receive CMOS or TTL signaling level data from lines  402 . Electronic controller  420  includes electronics which provide the CMOS or TTL signaling level data on lines  402 . LVDS drivers and receivers  400  convert the CMOS or TTL signaling level data to LVDS level data which is provided on cabling  404 . 
     Inkjet printing system  410  includes printhead assembly  412 . Printhead assembly  412  includes LVDS receivers and drivers  406  which are coupled to cabling  404 . In one operation, LVDS receivers and drivers  406  convert the LVDS level data received on cabling  404  to CMOS signaling level data provided on line  408  to module manager IC  450  of printhead assembly  412 . Module manager IC  450  operates similar to module manager IC  50  described above in reference to FIG. 6 to communicate with multiple printheads  440 , which are similar to the multiple printheads  40  described above in reference to FIG.  6 . 
     In another operation, LVDS receivers and drivers  406  convert CMOS signaling level data or signals provided from module manager IC  450  on lines  408  to LVDS level data or signals provided on cabling  404 . Cabling  404  provides the LVDS level data or signals to LVDS drivers and receivers  400  in electronic controller  420 . LVDS drivers and receivers  400  receive the LVDS level data or signals and convert the LVDS level data or signals to corresponding CMOS or TTL signaling level data or signals, which are provided on lines  402  to electronics in electronic controller  420 . 
     For example, in one embodiment of inkjet printing system  410  illustrated in FIG. 8, status data read from printheads  440  is provided back to module manager IC  450  and module manager IC  450  provides the status data as CMOS signaling level status data on lines  408 . In this example, LVDS receivers and drivers  406  convert the status data from CMOS signaling level data to LVDS level data, which is provided from printhead assembly  412  to electronic controller  420  with LVDS on cabling  404 . Therefore, any type of print data, non-print data, or other signaling can be communicated from electronic controller  420  to printhead assembly  412  or from printhead assembly  412  to electronic controller  420  employing LVDS on cabling  404 . In this way, any data or signals communicated between electronic controller  420  and printhead assembly  412  employing LVDS have substantially reduced voltage swings in cabling  404 , as compared to CMOS or TTL signaling level voltage swings. The reduced voltage swings in cabling  404  correspondingly reduce the amount of EMI conducted and/or radiated by cabling  404 , as compared to conventional cabling between an electronic controller and printhead assembly using standard CMOS or TTL signaling. 
     Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the chemical, mechanical, electro-mechanical, electrical, and computer arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.