Abstract:
A method and system receives a print job from a host device, parses the print job into individual print data for at least two separate printing devices, generates a random set of marks for identification of the print job, embeds the identification marks into the individual print data for a first printing device; and sends the individual print data and the marks to each printing device. Simultaneously, each printing device in the system receives its individual dataset for printing and the set of identification marks from the control unit and starts its print engine at a high speed. The first printing device prints its dataset and the identification marks on at least a first page of the printed dataset. The remaining printing devices then scan the roll of print media until they recognize the matching identification marks and begin printing their individual dataset on the roll of print media.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention generally relates to the field of printer systems, and more particularly relates to a method for aligning two or more independent printing systems.  
           [0003]    2. Description of Related Art  
           [0004]    High-speed printing systems are used by businesses to print a large volume of information such as bills and account statements. The printing system prints on a continuous, fan-fold type of media that is threaded through the machine. However, it is very difficult for each system to print duplex (both sides of the paper). Also, the system can only operate from one source, as it is critical that the variable data to be printed remains together.  
           [0005]    In order to print duplex when running continuous fan-fold forms at high speed requires large and expensive print mechanisms, or can be done by using more than one print mechanism that can only print on one side. When running more than one independent print engine that are separated by several meters, it becomes critical that the print data that is to match the second side be placed in conjunction with the data printed on the first print engine. Whether  2 , 3 , 4 , or more print engines are used, the data that is printed on the paper by each of the engines must be the matching data for the page.  
           [0006]    In non-automated methods, an operator is required to align the print engines by visually inspecting the print and manually indicating to the control unit that the print alignment is correct. This introduces the possibility of potential operator error, which wastes paper and costs valuable time.  
           [0007]    Therefore a need exists to overcome the problems with the prior art as discussed above, and particularly for a method of aligning two or more printing systems.  
         SUMMARY OF THE INVENTION  
         [0008]    According to a preferred embodiment of the present invention, a method and system receives a print job from a host device, parses the print job into individual print data for at least two separate printing devices, generates a random set of marks for identification of the print job, embeds the identification marks into the individual print data for a first printing device; and sends the individual print data and information about the marks to each printing device. Simultaneously, each printing device in the system receives its individual dataset for printing and the information for the identification marks from the control unit and starts its print engine at a high speed. The first printing device prints its dataset and the identification marks on at least the first page of the printed dataset. The remaining printing devices then scan the roll of print media until they recognize the matching identification marks and begin printing their individual dataset on the roll of print media. None of the printing devices are required to pause, slow down, or stop prior to printing their individual datasets. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a block diagram illustrating an automatically aligning printing system in accordance with a preferred embodiment of the present invention..  
         [0010]    [0010]FIG. 2 is a more detailed block diagram showing a control unit in the system of FIG. 1, according to a preferred embodiment of the present invention.  
         [0011]    [0011]FIG. 3 is a more detailed block diagram showing a printing device in the system of FIG. 1, according to a preferred embodiment of the present invention.  
         [0012]    [0012]FIGS. 4, 5 and  6  are operational flow diagrams illustrating exemplary operational sequences for the system of FIG. 1, according to a preferred embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    The present invention, according to a preferred embodiment, overcomes problems with the prior art by allowing two or more independent print mechanisms to be aligned such that print data that is placed on the paper matches in both registration and content without involvement from a machine operator; and does so in a manner that causes motion of paper media in all separated print mechanisms to be in unison without pauses or reduction in speed. All separate print engines are aligned under direction of a single control unit, and the single control unit prints sheets that match correctly without regard to the distance between the separate print units. This method takes advantage of a single control unit used to control multiple print engines, and intelligent print controllers located inside each print engine that are able to control optical mark sensors and control the flow of print data to the print engine. This method takes advantage of the single control unit to maintain simultaneous motion though all print mechanisms, protecting the integrity of the paper media path between the print engines; and takes advantage of the intelligent print controllers located inside each print engine to relieve the single control unit of the responsibility to maintain or be cognizant of the distance between each print engine.  
         [0014]    A preferred embodiment uses sensors previously used to verify that the print on each engine was correct to now automatically set proper alignment prior to printing the print data. Once the alignment has been completed, the sensors are returned to normal operation, which verifies every sheet printed subsequent to the automatic alignment. This is done without stopping or slowing down the paper media and without operator involvement.  
         [0015]    [0015]FIG. 1 illustrates an exemplary automatically aligning printer system according to a preferred embodiment of the present invention. The automatically aligning printer system  100  includes a host device  102  communicatively coupled to a control unit  106  having an automatic printer aligning application  116 , via a local area network interface  104 . The local area network interface  104  may be a wired communication link or a wireless communication link. The control unit  106  may also be communicatively coupled with the world-wide-web, via a wide area network interface (not shown) via a wired, wireless, or combination of wired and wireless local area network communication links  104 . Alternatively, the printer  106  may also be communicatively coupled locally to the computer system  102 . The control unit  106  is also communicatively coupled to at least two separate printing devices  110 , 112 . The printing devices  110 , 112  each contain an intelligent controller  118 , 120  and a continuous roll of media  114  is threaded through each machine.  
         [0016]    Each host system  102  may include, inter alia, one or more computers. The control unit  106  may include one or more computers and at least one computer readable medium  108 . The computers preferably include means for reading and/or writing to the computer readable medium. The computer readable medium allows a computer system to read data, instructions, messages or message packets, and other computer readable information from the computer readable medium. The computer readable medium, for example, may include non-volatile memory, such as Floppy, ROM, Flash memory, Disk drive memory, CD-ROM, and other permanent storage. It is useful, for example, for transporting information, such as data and computer instructions, between computer systems. Furthermore, the computer readable medium may comprise computer readable information in a transitory state medium such as a network link and/or a network interface, including a wired network or a wireless network, that allow a computer to read such computer readable information.  
         [0017]    The control unit  106 , according to the present example, includes a controller/processor unit  216  (shown in FIG. 2), which processes instructions, performs calculations, and manages the flow of information through the control unit  106 . Additionally, the controller/processor  216  is communicatively coupled with program memory  210 . Included within program memory  210  are an automatic printer alignment application  116  (which will be discussed in later in greater detail), an operating system platform  212 , and glue software  214 . The operating system platform  212  manages resources, such as the data stored in data memory  220 , the scheduling of tasks, and processes the operation of the automatic printer alignment application  116  in the program memory  210 . The operating system platform  212  also manages a graphical display interface (not shown), a user input interface (not shown) that receives inputs from the keyboard  206  and the mouse  208 , and communication interfaces  222  for communicating with the network link  104  and individual printing devices  110 , 112 . Additionally, the operating system platform  212  also manages many other basic tasks of the control unit  106  in a manner well known to those of ordinary skill in the art.  
         [0018]    Glue software  214  may include drivers, stacks, and low level application programming interfaces (API&#39;s) and provides basic functional components for use by the operating system platform  212  and by compatible applications that run on the operating system platform  212  for managing communications with resources and processes in the control unit  106 .  
         [0019]    In a preferred embodiment, as shown in FIG. 3, each printing device  110 , 112  includes an intelligent controller  118 , 120 , having an alignment application  316  and a verification application  314 , each application being communicatively coupled to a communication interface  306 , sensors  304 , and a print engine  302 . The print engine  302  is communicatively coupled to a printhead  320 . The printhead  320  is typically used to apply toner or ink  318  to a continuous roll of media  114 . In accordance with the preferred embodiments of the present invention, the output of electronic images can be applied to many different output mediums. The word “print”, as used herein, denotes the output ofelectronic image from digital representation in a computational system, to a physical medium, such as paper, plastic film, cloth, or other output medium as will be evident to someone of ordinary skill in the art in view of the discussion herein. Lastly, the data memory  308  is communicatively coupled to the intelligent controller  118 , 120  and may contain a document queue of print jobs  310 , and a configuration database  312 .  
         [0020]    [0020]FIGS. 4, 5 and  6  are operational flow diagrams illustrating exemplary operational sequences for the system of FIG. 1. The system enters the sequence at step  402 , wherein a control unit  106  receives a request to print data from a host device  102 . The control unit  106  processes the data, at step  404 , such that the correct print data is separated for direction into the correct printing device  110 , 112 . For example, in a duplex machine, the front side data maybe prepared for transmission to the first printing device  112 , and the back side data may be prepared for transmission to the second printing device  110 . Likewise, magnetic ink character recognition (MICR) data maybe separated to be sent to a MICR-capable printing device, and different color separations (blue, green, red, etc.) may be separated to be sent to yet another printing device.  
         [0021]    As is typical for the system, the control unit  106  applies encoded marks to the print job to allow the intelligent print controllers  118 , 120  to detect mismatched print data as the paper moves through the system. Having previously loaded (threaded) paper  114  through all of the separate printing devices, an operator allows the print job to start.  
         [0022]    The control unit  106 , at step  406 , builds unique print data to be printed which includes a trivial set of encoded marks, which are able to be sensed by the existing, inexpensive, limited-capability optical sensors  304  in each of the printing devices  110 , 112 . The encoded marks are designed, within the limitation of the optical sensor  304 , to be decoded into a 7-bit (1 to 127 decimal) number. Multiple sets of these encoded marks may be printed on one page, or on multiple pages if the page size is too small, to allow for a unique (“random”) numerical sequence to be described. The number of sets of the encoded marks is made to ensure detection of the unique numerical sequence; even with the loss of one or more of the sets because of poor read rate of the optical sensor, or poor print quality of the marks. Also, because of the unique pattern, failures in printing devices  110 , 112  that leave many sets of marks in the paper path are of no consequence.  
         [0023]    The control unit  106 , in step  408 , sends the “key” (description of the proper unique sequence) to each of the intelligent print engine controllers  118 , 120  located inside each of the printing devices  110 , 112 . The control unit  106 , at step  410 , sends the special print data containing the encoded marks to the first printing device  112 , and may also send the special print data to another of the multiple printing devices if the marks must be printed on both sides of the paper  114  for one or more devices past the second device  110 . The control unit  106 , at step  412 , then sends the previously separated print job, in proper separations, to each respective printing device  110 , 112 . The control unit  106 , at step  414 , then commands all printing devices  110 , 112  to begin moving paper  114  in unison.  
         [0024]    The first printing device  112 , at step  502 , receives its print data from the control unit  106 , starts its engine at step  504 , prints the special marks, then prints the print job at step  506 . The second (and third, and fourth, and . . . ) printing device  110 , at step  606 , watches for the encoded marks, and simply “prints” blank paper. As the encoded marks reach each subsequent printing device, the intelligent print controller  118 , 120  verifies the unique pattern required to signal proper alignment, at step  608 , and then prints the print job on the paper  114 , at step  610 , as it continues to move in a forward direction. The paper  114  does not slow, pause, stop, or reverse during the alignment. The media always travels at fill speed forward.  
         [0025]    If necessary, the intelligent print controller  118 , 120  may signal the master control unit  106  to stop and allow small (less than one sheet size) changes in the paper position be made by the individual intelligent print controller  118 , 120 . When this occurs, all print engines stop in unison, and no paper  114  can ever be moved backward or forward at a slow speed, and the control unit  106  would then begin paper movement on all print engines again in unison.  
         [0026]    Once the individual intelligent print controller  118 , 120  detected the correct encoded sequence, and begins to print the print job, it automatically switches to “verify” mode and uses the encoded marks normally added by the control unit  106  to begin the verification checking.  
         [0027]    The present invention can be realized in hardware, software, or a combination of hardware and software. A system according to a preferred embodiment of the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system—or other apparatus adapted for carrying out the methods described herein—is suited. A typical combination of hardware and software could be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.  
         [0028]    The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system—is able to carryout these methods. Computer program means or computer program in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or, notation; and b) reproduction in a different material form.  
         [0029]    Although specific embodiments of the invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments, and it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.