Patent Application
20060122951
The invention disclosed herein relates generally to mailing systems, and more particularly to high speed mail processing systems that utilize multiple printing modules for printing indicia and other information on mail pieces.
Mail processing systems for preparing mail pieces, e.g., stuffing envelopes, and/or printing postage indicia on envelopes and other forms of mail pieces have long been well known and have enjoyed considerable commercial success. There are many different types of mail processing systems, ranging from relatively small units that handle only one mail piece at a time, to large, multi-functional units that can process thousands of mail pieces per hour in a continuous stream operation. The larger mailing machines often include different modules that automate the processes of producing mail pieces, each of which performs a different task on the mail piece. The mail piece is conveyed downstream utilizing a transport mechanism, such as rollers or a belt, to each of the modules. Such modules could include, for example, a singulating module, i.e., separating a stack of mail pieces such that the mail pieces are conveyed one at a time along the transport path, a moistening/sealing module, i.e., wetting and closing the glued flap of an envelope, a weighing module, and a metering module, i.e., applying evidence of postage to the mail piece. The exact configuration of the mailing machine is, of course, particular to the needs of the user.
Typically, a control device, such as, for example, a microprocessor, performs user interface and controller functions for the mail processing system. Specifically, the control device provides all user interfaces, executes control of the mail processing system and print operations, calculates postage for debit based upon rate tables, provides the conduit for the Postal Security Device (PSD) to transfer postage indicia to the printer, operates with peripherals for accounting, printing and weighing, and conducts communications with a data center for postage funds refill, software download, rates download, and market-oriented data capture. The control device, in conjunction with an embedded PSD, constitutes the system meter that satisfies U.S. information-based indicia postage meter requirements and other international postal regulations regarding closed system meters.
Modern mail processing systems utilize digital printing techniques for producing images on a mail piece. Conventional digital printing techniques include bubble jet and ink jet, each of which produces an image in a dot matrix pattern. With digital printing, individual print head elements (such as resistors or piezoelectric elements) are selectively electronically stimulated to expel drops of ink from a reservoir onto a substrate, e.g., a mail piece. In either case, by controlling the timing of energizing of the individual print head elements in conjunction with the relative movement between the print head and the mail piece, a dot matrix pattern is produced in the visual form of the desired image. In the case of mail processing systems, the image may be, for example, an indicium that evidences payment of postage.
Digital printing technology has significant advantages when used in a mail processing system as compared to older technology that utilized either a flat platen or a rotary drum to imprint information, such as, for example, address information or an indicium, on mail pieces. For example, if some variable image data needs to be changed, it can easily be done through the installation of new or upgraded software versus having to replace the entire printing module, since the flat platen and drum are typically not separately removable. Moreover, greater printing speeds can be obtained as compared to conventional mechanical printing systems.
The use of a digital printing technology in mail processing systems, however, presents other issues that must be taken into consideration. For example, standard ink jet print heads must be stopped occasionally in order to perform maintenance routines. In particular, “drop-on-demand” style ink jet print heads are known to require periodic maintenance. Maintenance may include a “print head wipe” that occurs approximately every 500 prints, and has a duration of approximately 3 seconds. Maintenance also may include a “print head purge” that occurs after approximately every 3000 prints, and has a duration of approximately 14 seconds. Such maintenance requires the printing module to be inactive, i.e., not perform any print operations, for the period of time required to perform the maintenance. In high speed mail processing systems that can process mail pieces at rates up to 22,000 mail pieces per hour, it is necessary to stop the system completely to allow these maintenance periods to occur. Because of the high volume of mail pieces processed, even very short periods of down-time for maintenance can significantly impact the throughput of the system. For example, halting a system that typically processes 22,000 pieces per hour for only two minutes will reduce the throughput by 733 pieces per hour. If the maintenance is required to be performed at least once per hour, in an eight hour day the throughput of the machine will be decreased by almost 6,000 pieces. To minimize any down-time of the system, it is known to place two print heads or modules (collectively referred to hereinafter as print or printing modules) in series along the transport path, where only one of the printing modules is activated at a time. Thus, when one of the printing modules requires maintenance operations, it can be inactivated and the other printing module activated to print on the mail pieces. For example, if the first printing module requires maintenance, the first printing module is inactivated and the second printing module is activated. Mail pieces will pass through the first printing module, without being imprinted upon, to the second printing module, where printing will occur. When the second printing module requires maintenance, the second printing module is inactivated and the first printing module is activated. Mail pieces will be imprinted upon by the first printing module and will pass through the second printing module without being imprinted with any information.
The use of multiple printing modules in series, while alleviating the problem of reduced throughput, introduces new issues for the mail processing system. For example, to communicate with each of the printing modules, it is necessary to provide electrical switches to switch between each of the printing modules. In addition, each printing module requires its own separate printer controller to control operation of the print head. Each printing module having its own printer controller requires the duplication of both hardware and software that constitute the printer controller, which along with the switching mechanism required add significantly to the complexity and cost of the high speed mail processing system.
Thus, there exists a need for a high speed mail processing system that utilizes multiple printing modules without adding to the complexity, cost or size of the system while still maintaining full functionality required for printing.
The present invention alleviates the problems associated with the prior art and provides methods and systems for utilizing a single printer controller, or portions thereof, in conjunction with multiple print heads, thereby not adding complexity, cost or size to the system, while still maintaining the full functionality required for printing.
In accordance with embodiments of the present invention, a high speed mail processing system having multiple printing modules is provided with a single printer controller or portion thereof that is used to control the operation of all of the printing modules. Messages that originate from the control unit of the mail processing system include a header that identifies the intended recipient(s) of the message, and the single printer controller can route the message to the intended recipient(s) based upon the identification included in the header. Optionally, the message could be broadcast to all of the printing modules and only the printing module for which the message is intended will act upon the message.
According to other embodiments, the printer controller can be separated into different parts for performing different functions related to the printing modules, including for example, data management functions and maintenance functions, and only a single part of the printer controller is provided to control respective functions for all of the printing modules in the system. By allowing the multiple printing modules to share a controller, the need for duplicated hardware and software is removed, thereby decreasing both the complexity and cost of the system.
Therefore, it should now be apparent that the invention substantially achieves all the above aspects and advantages. Additional aspects and advantages of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. Moreover, the aspects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The accompanying drawings illustrate a presently preferred embodiment of the invention, and together with the general description given above and the detailed description given below, serve to explain the principles of the invention. As shown throughout the drawings, like reference numerals designate like or corresponding parts.
In describing the present invention, reference is made to the drawings, wherein there is seen in
Mail processing system 10 further includes two printing modules: an upstream printing module 20 and a downstream printing module 22. It should be understood that while the description below is made with respect to two printing modules 20, 22, the present invention is not so limited and more than two printing modules may be provided. The printing modules 20, 22 preferably utilize digital printing technology, and include a respective print head 26a, 26b. According to an embodiment of the present invention, the printing modules 20, 22 are controlled by a single printer controller 30, instead of each printing module 20, 22 being provided with its own printer controller as done in the prior art, thereby deceasing both the complexity and cost of the system 10. The printer controller 30 is coupled to the controller 12. The printer controller 30 controls all operations of printing modules 20, 22 related to management of data from the controller 12 and maintenance of each print head 26a, 26b. Management of the data can include, for example, the decryption (if encrypted when received from the controller 12), grouping, formatting and distribution of data between groups of ink jets in the appropriate print head 26a, 26b, generation of the timing signals necessary for firing the ink jets of the appropriate print head 26a, 26b, collection of usage information of the print heads 26a, 26b, and detection of overheating conditions in the print heads 26a, 26b. Maintenance functions could include, for example, controlling positioning of the print heads 26a, 26b to ensure the print heads 26a, 26b are in a capped position when not printing, ensuring the print heads 26a, 26b are capped properly when in the capped position, ensuring ink is present in either the ink reservoir(s) (not shown) or the print heads 26a, 26b, ensuring ink is being properly supplied from the reservoir(s), monitoring the voltages being applied to fire the ink jets of the print heads 26a, 26b, and monitoring for error conditions during operation including improper positioning of the print heads 26a, 26b, overheating of the print heads 26a, 26b, out of ink conditions, etc.
Data and control signals from the controller 12 are transmitted to the printer controller 30 via data line 34. Data and control signals are transmitted to the printing modules 20, 22 via data lines 40, 42 respectively. A transport 44, including, for example, rollers and/or belts, is utilized to transport mail pieces along a transport path through the mail processing system 10 in the direction indicated by arrow A. The printing modules 20, 22 are arranged serially along the transport path. The transport 44 will transport the mail pieces past the printing modules 20, 22 such that printing by one of the printing modules 20, 22 can occur on each mail piece. Sensors (not shown) located along the transport 44 provide signals to the controller 12 to indicate the position of a mail piece on the transport 44. Only one of the printing modules 20, 22 is activated at a time. For example, if the printing module 20 is currently deactivated, mail pieces will pass through the printing module 20, without being imprinted upon, to the printing module 22, where printing will occur. When the printing module 22 is made inactive, such as, for example, when maintenance is necessary, the printing module 20 is activated. Mail pieces will be imprinted upon by the printing module 20 and will pass through the printing module 22 without being imprinted with any information.
Alternatively, the printing modules 20, 22 can be arranged in a parallel fashion and mail pieces diverted to the printing module that is currently activated. When the currently active print module requires maintenance, it can be deactivated, the other print module activated, and the mail pieces diverted along the transport path to pass under the currently active printing module.
Since the printer controller 30 of the present invention is utilized to control both printing modules 20, 22, it is necessary to distinguish the intended recipient, i.e., either print head 26a or print head 26b, of messages, e.g., print messages and commands, from controller 12. This will ensure that messages intended for the printing module 20 and print head 26a are not improperly acted upon by the printing module 22 and print head 26b. To achieve this, each of the print heads 26a, 26b is provided with a unique identification number, and every message provided from the controller 12 to the printer controller 30 includes a header that specifies the identification number of the print head 26a, 26b for which the message is intended. The identification number may be, for example, a serial number or the like, or an address of the print heads 26a, 26b. Based upon the identification of the intended print head 26a or 26b in the message from the controller 12, the printer controller 30 will act upon and route the message to the proper print head 26a or 26b using either data line 40 or 42, respectively. Optionally, a predetermined fixed value for the header could be used to signify that a message from the controller 12 is a broadcast message intended for every print head in the system 10. In this situation, the printer controller 30, upon determining that the message is a broadcast message intended for all print heads in the system 10, will act upon and route the message to all print heads in the system 10. Thus, each print head in the system 10 will receive commands from the printer controller 30 and respond accordingly based on the message from the controller 12. The use of broadcast messages allows optimization of the time needed to complete various operations that need to be performed in preparation for printing. This time optimization is achieved by each of the printing modules being prepared to print prior to a print command, and therefore can execute the printing task without any additional preparation time required, thereby reducing the total amount of time required to execute the task.
According to an alternative embodiment illustrated in
Optionally, the data lines 240, 242 could be combined into a single data line (similarly as described with respect to
The above description requires that all messages from the PHC 330 be passed through one or more of the PMCs 332a, 332b via data lines 340, 342. Optionally, the PHC 330 may also be coupled directly to each print head 26a, 26b by data lines 350, 352. Thus, any messages provided from the controller 12 to the PHC 330 that do not require any maintenance operations, and thus do not need a PMC to be performed, can be passed directly to the intended print head 26a or 26b via a respective data line 350, 352 without having to pass through either of the PMCs 332a or 332b.
Optionally, the data lines 340, 342, as well as 350, 352, could be combined into a single data line (similarly as described with respect to
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as limited by the foregoing description.
