Abstract:
An improved postage meter mailing system utilizes a meter vault operated under the control of a microcontroller mounted in a secure housing. The microcontroller of the meter vault has a communication device for receiving and transmitting data messages and non-volatile memory for storing program data and other data. A printer is utilized for printing a postage indicia. The printer operates under the control of a microcontroller mounted in a secure housing. The microcontroller of the printer has a communication device for receiving and transmitting data messages and non-volatile memory for storing program data and other data. An interface provides a communication path between the meter vault and the printer. The non-volatile memory of the meter vault has stored therein a program version number for identifying the control program version. The non-volatile memory of the printer has store therein a software update number for identifying associated meter vault programs which utilize the update software. Upon system start-up, the print head microcontroller requests the meter vault microcontroller to transmit the control program version and number and determines whether the control program require the update software and if so transmits the update software.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a postage metering system that utilizes a digital printer and, more particularly, to a postage metering system wherein the postage metering system includes a meter vault and a replaceable digital printing unit which are physically separated. 
     Generally, a postage metering system includes a meter vault which accounts for the postage printed by a printing unit. The meter vault is comprised of a programmable microcontroller having a program memory for storing the system control program data. In an attempt to employ digital printer, such as, ink-jet, in the postage metering systems, it has been found that a print module configuration which includes the print heads, drivers and graphic imaging system within a single secure package is desirable. An electronic communication channel is provided between the meter vault and the print module to allow the communication of critical accounting and other data between the meter vault and the print module. This channel may also be used to allow communication between the print module and a mailing machine. 
     It is conventional practice to provide system software updates from time to time which either correct software defects, increase system efficiencies or add system functionality. Submitting the meter vault to system software updates or modifications has typically been accomplished in one of three ways. Under certain circumstances the meter vault must be taken out of service and returned to the manufacture where the security housing is removed and special equipment is used to load updated software into the program memories of the system. If sufficient unallocated program memory exists, it may be possible to connect a special service device to a communication port of the meter vault and down load the updated software into the program memory or other usable non-volatile memory. The service device must be specially equipped to preserve the security of the meter vault housing and internal circuit security of the meter vault. Another way is to trade out the existing meter vault with a new meter vault. All of these processes represent substantial time and cost consequences. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide a convenient means of up-dating the control program data for the meter vault and the mailing machine which overcome the time and cost consequences of the conventional processes. 
     A postage meter system in accordance with the present invention includes a base unit, more commonly referred to as a mailing machine, which serves as a platform for the meter unit. The base includes a microcontroller system which is responsible for controlling the transportation of envelopes in a sequential manner to a printing location whereat the printing unit can print a postage indicia and any other additional information, such as, an ad slogan, delivery address or bar code on the envelope. In a preferred configuration, it is contemplated that printing will accrue during relative motion between the envelope and the printing unit associated with the meter. Therefore, the microcontroller system in the base will be responsible for relatively precise control of the motion of the envelope through the printing location. 
     The metering is provided by way of two independent units which are a vault and a printer. The vault accounts for and dispenses funds for postal payment. Communication between the mailing machine, vault and printer is facilitated through a printer interface unit. The meter vault communicates with the print head to transfer encrypted messages for postage amount, piece count, and digital tokens. A digital token represents an alphanumeric sequence generated by using any suitable algorithm which uniquely identifies the postage indicia as originating from a particular postage meter system and verifying that that postage meter system is authorized for use by the Postal Authorities. Meter vault communications are routed to the print head through the printer interface. The meter vault securely communicates with the print head using any suitable digital encryption technique. 
     The printer interface serves as a junction board for the mailing machine, meter vault, slogan box, and print head. This minimizes the number of connection points in the system. The printer interface provides the connections for a serial communication linkage and unregulated DC power from the mailing machine to the meter vault, transfers print command and status signals between the mailing machine and print head, interfaces the slogan box to the print head, supports a unique serial link between the meter vault and print head, and regulates logic and print nozzle power from the mailing machine to the print head. 
     The slogan box stores graphics images representing the fixed part of the standard indicia (e.g., the eagle printed on US mail), low-value indicia, permit mail indicia, town circle (where appropriate), inscriptions, and customer slogans. It also stores the fonts for printing the variable data on the mail piece. All of the graphics data is either encrypted or signed, that is, subject to other types of encoding algorithms in the slogan box non-volatile memory. The encryption or signing is done at the manufacture&#39;s facility. Only the print head contains the necessary decryption key to properly interpret the data. 
     The communication by the meter vault includes encrypted information. Only the meter vault and the print head know the proper keys to utilize the information. The keys are stored in an ASIC on the print head to reduce the opportunity for fraud. The microcontroller on the print head controls the printing operation including loading of NVM, decoding of messages with assistance of a DES engine on the print head ASIC, and initiating of printing. The microcontroller helps to reduce the complexity of the ASIC. 
     The print head ASIC decodes the mail position for printer sequencing, provides the proper timing for driving the print nozzles, supports external ink supply monitoring, interfaces to the NVM; support external communications, and performs self-test functions. The print head NVM also stores inscription representations. The meter vault stores a table of enabled inscriptions. When the operator at the mailing machine wishes to select an inscription, the print head transfers a list of the available options to the meter vault. The vault screens for only the enabled inscriptions and sends the information to the mailing machine. The operator&#39;s response is forwarded from the meter vault to the print head. 
     As part of the system start-up process, the print head issues a message to the meter vault which directs the meter vault microcontroller to receive updated program data, only if, that updated program data version has not already been written to the non-volatile memory of the meter vault. The print head then encrypts the updated program data and transmits that encrypted data to the meter vault. The microcontroller of the meter vault then decrypts the updated program data and stores the data in the non-volatile memory of the meter vault. The program update code is loaded into the print module after fabrication by the manufacture and prior to shipment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic of a postage metering system in accordance with the present invention. 
     FIG. 2 is a schematic illustration of the communication path between the meter vault, mailing machine and print head units and of the respective control systems in accordance with the present invention. 
     FIG. 3 is a process diagram of the start-up process of the postage meter system in accordance with the present invention. 
     FIG. 4 is a process diagram of the slogan selection process of the postage meter system in accordance with the present invention. 
     FIG. 5 is a process diagram for mail processing of the postage meter system in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, the postage meter system, generally indicated as  11 , includes a mailing machine base  12 . The mailing machine base  12  is of any suitable conventional design and, in the preferred embodiment, includes a feeder section  13 , singulator  14  and scale section  15  positioned serially along a mail flow path. Following the scale section  15  is a print station at location A which is followed by a stacker  17 . Any suitably designed feeder section  13 , singulator section  14 , scale section  15  and stacker section  17  may be used. The operation of the respective section  13 ,  14 ,  15 , and  17  is under the control of a mailing machine controller  21 . Power to the system is provided by a conventional power supply  19 . It should be appreciated that the mailing machine controller  21 , in the preferred embodiment, will control such additional functional systems as the operator keyboard and display, unsecured departmental accounting (not shown) and other convention system functions. As depicted in FIG. 1, a rates programmable read only memory (PROM  22 ) is detachables mounted to the mailing machine controller  21  to provide rate information to the mailing machine controller in any suitable conventional manner. 
     Also, housed in the mailing machine is a printer interface  23 , slogan box  25 , meter vault  24  and print head/controller  27 , hereafter referred to as print head  27 . The print head  27  is mounted to rails  30  and  31  by any suitable means to be positionable, by any convention means such as by a motor (not shown) between a first position “A” which is the print position, a second position “B” which is a tape print position, and a third position “C” which is a cleaning position. At position “C” the print head  27  is brought into contact with a nozzle cleaning system of any suitable design such that, for example, wherein ink jet print technology is utilized by the print head  27 , the nozzles may by cleaned. The positioning of the print head  27  along the rails  30  and  31  is under the control of the mailing machine controller utilizing any suitable conventional control means. 
     Also, the mailing machine  12  includes provisions for allowing the external interface of a external interface unit (EIU  26 ) to the printer interface  23  by any conventional means. The EIU  26  provides additional microprocessing functionality to the system  11  utilizing any suitable method. 
     Referring to FIG. 2, the meter vault  24  includes a source accounting memory  40  and  41 , program memory  42 , ASIC  43 , CPU controller  44 , and keyboard/display  45 . As more specifically described subsequently, the ASIC  43  provides two RS-232 communications ports  46  in any suitable conventional means for facilitating communications with the mailing machine  21 . 
     The communication port  46  is modified to include an extra pin for receiving DC power from the mailing machine. It should be appreciated that the keyboard and display  45  is provides an operator or postal agent a means of recharging the accounting registers of the accounting memory  40  and  41  through the keyboard in any suitable conventional manner. 
     The mailing machine controller  21  is comprised of a controller CPU  50 , code ROM  51 , code RAM  52 , user input/output  53 , motor controller  54 , sensor controller  55 . Also provided is a scale interface  56  and UART interface  57 . The UART interface  57  is of any conventional design for allowing asychronous serial communication. Of principle concern to the preferred embodiment of the present invention is that the UART interface facilitates communication between the mailing machine controller  21  and the other system units  23 ,  24 ,  25 ,  26  and  27 . 
     The print head  27  is comprised of a CPU controller  60 , nonvolatile memory units  61  and  62 , ASIC  63  and print units  64 ,  65 ,  66 . In the preferred embodiment it is contemplated to use multiple ink jet printing units. 
     Meter vault  24  communications to the print head  27  are routed through the printer interface  23  along communication path P 47 . The meter vault  24  securely communicates with the print head  27  using DES encryption. A number of encryption keys are preloaded into the ASIC  63  of the print head  27  and ASIC  43  of the meter vault  24 . This will make discovering the keys impossible without reverse engineering of the ASIC  43  or  63 . Communications path  47  is also used to select inscriptions and slogans in conjunction with the slogan box  25 . A printer interface path P 46  provided for electrical communication with the EIU  26 . As aforenoted, the EIU  26  represents an external unit which can be attached to the meter vault  24  to provide enhanced capability to the meter vault  24  when the meter vault  13  is used in combination with a defeatured mailing machine. 
     The printer interface  23  serves as a junction board for the mailing machine  21 , meter vault  24 , print head  27  and a slogan box  25 . By providing specific communication pathes P 13 , P 14 , P 17 , P 37 , P 46 , P 47 , P 57  within the printer interface  23 , the individual subsystems can be isolated in such a manner to remove the necessity for interdependent security measures. 
     The slogan box  25  stores graphics images representing the fixed part of the standard indicia (e.g., the eagle printed on US mail), low-value indicia, permit mail indicia, town circle (where appropriate), inscriptions, and slogans. It also stores the fonts for printing the variable data on the mail piece. All of the graphics data is either encrypted or signed in the slogan box  25  non-volatile memory (not shown). Only the print head  27  contains the necessary decryption key to properly interpret the data. Because of the different indicia formats, each country will have its own indicia graphics, therefore its own slogan box  25  product code number. 
     When a new print head  27  is positioned in the mailing machine  17 , the controller  21  checks the local NVM  61  and  62 ; if it is un-initialized, the controller reads the slogan box  25  to retrieve the necessary graphics information. The print head  27  decrypts or verifies this data and programs it into its NVM  61  and  62 . In the event that the print head NVM  61  and  62  are smaller than the slogan box NVM, only the subset of graphics necessary for a particular mail run is loaded into the print head NVM  61  and  62 . If the NVM  61  and  62  should become corrupted, e.g., fail a checksum test, the controller  60  can request a new memory download as though it were newly installed. 
     When the mailing machine microcontroller  21  initiates the meter ad selection option as a result of operator selection via the user I/O  53 , the slogan box  25  will transfer a text description of each of its slogans to the mailing machine microcontroller  21  through the print head  27  and meter vault  24 . Once the operator responds with the selected slogan to print by selection of the appropriate operator key on the mailing machine  11 , the slogan box  25  transfers the bit-map slogan image to the print head  27  if it is not already loaded in the print head NVM  61  and  62 . The slogan box  25  electrically connects to the print head  27 . 
     The print head  27  prints the indicia including postage amount, digital tokens, piece count, and date as well as an optional inscription and slogan on each mail piece. The fixed part of the image, fonts for the variable parts of the image, and inscription bit-maps are programmed into the print head&#39;s NVM  61  and  62  when the print head is first installed in the mailing machine  17 . The meter vault  24  will send a message to the print head  27  indicating the format of the town circle. The print head  27  obtains the town circle information as either a text string from the meter vault  24  or a bit map from the slogan box and programs its NVM with the data. For each mail piece, the meter vault  24  transfers the variable indicia information such as the postage amount, digital tokens, meter serial number, and piece count to the print head  27 . The print head controller  60  programs registers (not shown) in the ASIC  63  with this information. When the mailing machine microcontroller  21  commands the print head  27  to print, the ASIC  63  combines the fixed and variable parts of the image for printing by the print units  64 ,  65  and  66  utilizing any suitable technique. 
     The interface with the meter vault  24  includes encrypted information; only the meter vault  24  and the print head  27  know the proper keys to utilize the information. The keys are stored in an ASIC  63  on the print head  27  and the meter vault ASIC  43 . 
     The controller  60  on the print head  27  controls the printing operation including loading of NVM  61  and  62 , decoding of messages and initiating of printing. 
     The print head ASIC  63  also decodes the mail position for printer sequencing, provides the proper timing for driving the print nozzles, supports external ink supply monitoring, interfaces to the NVM  61  and  62 ; supports external communications, and performs self-test functions. The print head NVM  61  and  62  also stores inscription representations. The meter vault  24  stores a table of enabled inscriptions when the operator at the mailing machine  11  wishes to select an inscription, the print head  27  transfers a list of the available options to the meter vault  24 . The vault  24  screens for only the enabled inscriptions and sends the information to the mailing machine microcontroller  21 . The operator response is forwarded from the meter vault  24  to the print head  27 . 
     Referring also to FIGS. 3,  4  and  5 , it is observed that the meter vault  24  may have any suitable known independent housing and internal security measures as well as the print head  27  may like-wise have independent housing and any suitable internal security since critical communication between the mailing machine controller  21 , meter vault  24  and print head  27  are secure communications. Particularly, referring to FIGS. 3,  4  and  5 , during the system start-up process, the print head  27  generates a random number which is then encrypted by the ASIC  63 . The random number is transmitted via path P 47  in the encrypted and clear form to the meter vault  24 . The meter vault  24  decrypts the random number and compares with the clear text. If a match is determined, then the meter vault  24  generates a message of critical data including the random number. The meter vault message is encrypted and transmitted along path P 47  to the print head  27 . The message is then decrypted and, if the random number transmitted matches the generated random number, the encrypted information is stored in NVM  61  and  62  for use in subsequent printing. The print head  27  then transmits a request to the meter vault  24  along path P 47  to send the program software version number. In response, the meter vault  24  sends the software version number along path P 47  which is received by the print head  27  and compared to a software version number stored in the non-volatile memory  61  or  62  of the print head  27 . If the version number transmitted to the print head  27  is equal to or greater than the version number stored in the non-volatile memory  61  or  62  of the print head  27  then the system is ready for normal operation. If the version number transmitted to the print head  27  is less than the version number stored in the non-volatile memory  61  or  62  then the print head  27  transmits the updated program data to the meter vault  24  which stores the updated program data in its non-volatile  40  or  41 . The system is now ready for normal operation. 
     Particularly referring to FIG. 4, in the manner described above, an operator may submit a query to the slogan box  25  for available slogans via paths P 14  and P 47 . The slogan box  25  transmits the slogan descriptor information via path  47  to the meter vault  24  which mask the unusable postal inscriptions. The meter vault  24  than relays the modified message to the mailing machine controller  21  for presentation to the requester. The requester than may a selection which the mailing machine controller  21  transmit via path P 17 , P 57  to the slogan box  25 . The slogan box  25  then transmits the data for the graphic image via path P 57  to the print head  27  which stores the graphic information in the memories  61  and  62 . The print head  27  then transmits via path P 17  an information received to the mailing machine controller  21 . 
     Referring now to FIG. 5, to process mail items, a postage value is either operator selected or determined based upon data from the scale  15  via the scale interface  56 . The mailing machine controller  21  transmits the appropriate postage value to the meter vault  24  via path P 14  which then accounts for the postage value. The meter vault  24  then encrypts the critical accounting data and transmit the encrypted data via path P 47  to the print head  27  where the data is decrypted. Once the data is successfully decrypted, the print head  27  transmits an OK to print to the mailing machine controller  21  via path P 17 . Upon receipt of the OK message from the print head  27 , mailing machine controller  21  then transmits along path P 17  a print enable and printing is commenced. 
     It should now be appreciated that the afore described system provides the benefit of unlacing system security and provides a method of generating secure communications between system units.