Thermal mechanism for printing fixed and variable information and postage meter having such a mechanism

Abstract: A high speed thermal printing mechanism having a dichotomized printing sequence. The thermal printing mechanism is particularly useful for printing postal values and indicia upon postage tape in a variable and fixed format, respectively. The variable information can be imprinted by a thermal head (30) under the influence of a microprocessor. The fixed information can be imprinted by an etched thermal print screen on a rotatable drum (27).

Description: The invention relates to electronic postage meters and to thermal printing mechanisms. In the past, electronic as well as mechanical postage printing devices featured rotatable printing drums with settable printing wheels for printing postal values. US-A-4 447 818 discloses a thermal printing mechanism having a plurality of recording stations each provided with a respective thermal printing head and a respective dispenser for thermal ink transfer sheet. Recording sheets are fed along a path passing sequentially through the recording stations to allow multi-coloured printing. More recently, with the advent of automated postage stations, thermal printers have replaced the previous fixed dies for printing postage. The thermal printing mechanisms are uniquely adaptable for use within these automated postage stations, in that they are capable of printing indicia, slogans, postal values, and other postage information in a simple manner. These thermal printing mechanisms are easy controlled by a microprocessor that initiates voltage pulses for heating the thermal printing elements to rapidly provide a postage stamp. While the thermal printers are relatively fast as compared with the previous mechanical drum printers however, they are relatively slow when printing indicia, such as an eagle stamp, when considering the speed of microprocessor signals. This problem results from the large amount of electronic control required to print an eagle indicia. It has been discovered that the thermal printing of postage can be further speeded by dichotomizing the printing of the postal information into a fixed and variable format. The variable postage data such as postal value and data is easily initiated through electronic input to a thermal head printer as previously accomplished. However, this invention now contemplates the thermal printing of indicia such as the eagle stamp, postage meter identification number and optional slogan, as fixed information. This fixed information is now thermally printed separately from the variable, electronically controlled data by another thermal printer having a fixed unalterable thermal printing screen carried by a rotatable drum. The two separate thermal printings form a composite of the final complete postage stamp by maintaining proper sequential registration between fixed and variable printings. The above arrangement not only provides for a speedier thermal printing of postage, but also has the further advantage of enabling better postage meter security. This may be accomplished by the fact that the meter number and eagle indicia have a unique design and are additionally in place within the system. Such indicia cannot be easily altered or modified within the course of normal postage meter operation. In United States Patent No. 4,446,467, issued to Ryohei Takiguchi et al, on May 1, 1984, a heat sensitive recording sheet is disclosed. The recording sheet is print activated by means of a flash lamp operating in the light range of 400-550nm. The Takiguchi et al patent also teaches the use of a print head to produce a variable printing pattern in response to a microprocessor controlled signal. In the United States Patent No. 3,934,503, issued to Layton C. Kinney et al, on January 27, 1975, a thermal stencil screen is shown for the production of lithographic or silk screen plates by means of igniting and removing ink impervious areas disposed upon the print plate master. It is an object of this invention to provide an improved electronic postage meter having a thermal printing mechanism. It is another object of the invention to provide an improved, high speed thermal printing mechanism that prints a composite postage impression or stamp comprising both fixed and variable information. According to one aspect of the invention, there is provided a printing mechanism according to claim 1. According to another aspect of the invention, there is provided an electronic postage meter according to claim 2. The first thermal printing means comprises a rotatable drum having a screen on its peripheral surface containing fixed indicia, such as a pattern of an eagle. A heat source is provided within the drum to project energy through open portions of the screen to transfer ink from a ribbon to a postage tape. A microprocessor preferably controls voltage pulses provided to the second thermal printer which preferably contains a printing head having individual heating elements. The desired postage to be printed is preferable entered via a keyboard that is electrically connected to the microprocessor and that provides electronic signals to initiate the voltage pulses. A display is also preferably connected to the keyboard to indicate the selected postage value. A slogan can be optionally printed by the drum of the first thermal printer, which preferably has the means for inserting a second screen. A cutting mechanism may be provided upstream from the first and second thermal printers to cut different tape lengths in accordance with the optional printing of a slogan. The invention will be better understood and will become more apparent with reference to the accompanying drawings, which show an explanatory embodiment of the invention, and in which; Figure 1 is a perspective view of an electronic postage meter in accordance with one embodiment of this invention; Figure 2 is a block diagrammatic view of the electronic system of the postage meter of Figure 1; and Figure 3 is a schematic view of the thermal printing mechanism for the postage meter of Figure 1. Generally speaking, the electronic postage meter of this invention features a high speed thermal printing mechanism that provides a composite stamp comprising both fixed and variable thermally printed information. High speed is achieved by eliminating the former complex electronic control necessary to replicate ornamental indicia or logos. Such indicia are, according to one embodiment of this invention, thermally printed by an unalterable etched screen supported upon a rotating drum. Variable information is electronically controlled by a microprocessor and thermally printed in the spaces provided in the already printed fixed design. For the purposes of brevity, like elements will be provided with the same designation throughout the subsequent description. Now referring to Figure 1, an electronic postage meter 10 is illustrated. The postage meter 10 is provided with a keyboard 11 for introducing into the system variable information, such as the postage selected to be printed. A display 12 is electrically connected to the keyboard 11 for indicating the selected and printed postage and for informing the user of account balances and other operating information. Similar keyboards and displays are shown and described in United States Patent No. 3,938,095, issued to Frank Check, Jr. et al, the disclosure of which is hereby incorporated herein. The postage meter 10 has a slot 13 from which the printed postage tape (not shown) is ejected. Input and output jacks may be provided to connect peripheral equipment, such as telecommunications equipment to the postage meter 10 as required. Referring to Figure 2, a schematic diagram of the electronic controls for the postage meter 10 of Figure 1, is depicted. The meter 10 is preferably operated by means of a microprocessor, of which the central processing unit (CPU) 14 is the operating center of the system. The multi-purpose ROM/RAM I/O device 15 connects to the CPU 14 through a conventional bus. The keyboard 11 and display 12 are likewise connected, and are scanned and driven by decoders 16 in a conventional manner to enable input and readout functions. Other peripheral equipment can likewise be connected into the system through device 15. Printer logic and driver circuits 17 receive information from the ROM/RAM I/O device 15 and translate these electrical signals into suitable, sequential voltage pulses to heat the thermal heating elements in the thermal printing head 18 of the variable information printing station 30 of the thermal printing mechanism shown in Figure 3. The thermal printing head 18 can be one of the type available commercially from RICOH Company LTD., San Jose, California, or KYOCERA Company, Kyoto, Japan. Such a typical printing head is shown and described in United States Patent No. 4,429,318, issued January 31, 1984, to Kobata. In the print head 18 at the variable information print station 30 of Figure 3, it is preferable that the heating elements be formed in a single row and arranged perpendicular to the direction of travel of a paper postage tape, as described hereinafter. For best results, there are about 224 elements in the row. The elements are heated as required for the purpose of melting an ink composition on a thermal transfer ribbon 23 (Fig. 3). The ink on the transfer ribbon is caused to be lifted off the ribbon at the point of heating and transferred to the paper postage tape traveling in conjunction with the thermal postage tape. The CPU 14 controls the sequencing of motor drivers 19 which are used to dispense the tape and ink ribbon, as will be described in more detail with respect to the print mechanism, depicted in Figure 3. Referring now to Figure 3, the thermal printing mechanism 25 comprises two, adjacent thermal printing stations 20 and 30, respectively. The thermal printing stations 20 and 30 are disposed along a postage tape feed path, defined by arrows 40. The first printing station 20 thermally prints the fixed indicia, such as the postage eagle insignia, upon the postage tape. The second printing station 30, as aforementioned, thermally prints the variable postage information, such as postage value, upon the postage tape. Printing stations 20 and 30 operate in sequence and are electrically and mechanically in registration with each other, such that the two printings upon the tape properly form a composite, or completed postage stamp. The postage tape is dispensed from a tape supplying roll 21 at the lefthand side of mechanism 25. The roll 21 is rotatively driven by one of the motor drivers 19, previously mentioned in the exposition of the circuitry of Figure 2. Another motor driver 19 is utilized to dispense a thermal ink transfer ribbon 23 from supply spool 22 by driving take-up spool 29, as shown. The dispensed ink transfer ribbon 23 meets the postage tape at the nip 24 created by the support roller 26 and thermal printing drum 27. From here, the ribbon 23 and the postage tape are carried together forwardly along the tape feed path 40 past printing stations 20 and 30, with the imprinted postage tape ejecting at point 28, corresponding to ejection slot 13 of Figure 1, and the spent transfer ribbon 23 being stored upon take-up spool 29. The fixed information printing station 20 comprises an idler belt 31 carried by three rollers 26, 32, and 38 of which roller 32 may be rotatively driven. The idler belt 31 provides support for the postage tape as it is carried into and out of contact with the thermal printing drum 27. The thermal printing drum 27 has an "eagle" indicia etched in a screen 33 carried by one-half the circumference of the outer drum surface. A heat or flash lamp 34 is disposed at the center of the drum, and irradiates the thermal ink transfer ribbon 23 through the open spaces in the etched screen 33. The image of the "eagle" is transposed by the melting ink of the ribbon which is henceforth transferred to the postage tape disposed adjacently the transfer ribbon 23. The drum 27 is made to rotate counterclockwise one complete revolution for each section of postage tape with which it comes in contact. The drum 27 has an open window over one-half of its circumference that may be filled with another etched screen carrying a slogan and/or logo. The slogan screen 35 is carried by a drum insert member 36, which is introduced (arrow 37) into the drum 27 with screen 35 placed opposite the screen 33. The resulting structure, therefore, fills the entire circumferential surface of drum 27, and the slogan is printed along side of the "eagle" indicia. As will be obvious to the skilled practitioner, the slogan will require a tape segment of double length. This is accomplished by the cutter blade 39 located upstream of the thermal printing station 20. As the tape supply roll 21 dispenses the postage tape, the tape is caused to move between feed rollers 41, which are driven in synchronism with printing drum 27 and the tape supply roll 21. In normal operation, the cutter blade 39 located between feed rolls 41 will cut a standard tape segment. When the slogan insert member 36 is in place within drum 27, a switch or sensor (not shown) in the drum 27 will cause the supply roll 21 and the cutter blade 39 to provide a double length of tape. This operation may also be programmed through the keyboard 11 and the microprocessor circuitry of Figure 2, where the user wants the option of only printing the slogan at specific times. The postage tape after having been imprinted with fixed information at printing station 20, will then move to the variable information printing station 30, as aforementioned. As the postage tape is traveling past the thermal head 18, the thermal ink transfer ribbon 23 is also traveling in conjunction with the tape. In response to output commands from the microprocessor, the thermal elements of the thermal head 18 are heated in a patterned sequence to create the desired image line-by-line on the tape traveling past the head as the ink coating on the thermal transfer ribbon is heated and lifted from the thermal transfer ribbon and deposited on the paper tape. The microprocessor will initiate the proper voltage pulses to actuate the heating elements in the print head 18. The variable information will be imprinted upon the postage tape in the open spaces provided within the alrady printed indicia. The postage tape is then discharged from between discharge rollers 42, and the spent transfer ribbon 23 is stored on reel 29. The upper discharge roller 42 is spring biased to provide tension in the ribbon 23, for proper feed and storage purposes. It will be understood that the drawings and description of this invention are exemplary, and are meant only to provide an understanding and best mode explanation of the invention. Having thus described the invention, what is desired to be protected is presented by the appended claims.

Claims: A thermal printing mechanism for the printing of indicia and numerical values in a respective fixed and variable format, said thermal printing mechanism comprising: means defining a tape feed path (40); means (21, 39, 41) for dispensing lengths of tape along said feed path; a first thermal printing station (20) disposed along said feed path for printing said fixed indicia upon said tape and including a heat source (34) and a rotatable printing drum (27) substantially surrounding said heat source and supporting a screen (33) around circumferential portion of the drum and containing said fixed indicia; a second thermal printing station (30) disposed adjacent said first thermal printing station for printing variable information upon said tape, said second thermal printing station including thermal heating elements responsive to voltage impulses initiated by electronic signals related to a numerical value; means (22) for dispensing a thermal ink transfer ribbon (23) between said first and second thermal printing stations and said tape to travel in conjunction with said tape along the tape feed path past the first and second printing stations, whereby ink from the ink transfer ribbon (23) can be transferred to said tape by each of said first and second thermal printing stations operable in sequence and in electrical and mechanical registration with each other to form a composite print on said tape; and an idler belt (31) carried by rollers (26, 32, 38) to provide support for said tape and said thermal ink transfer ribbon to carry said tape and said thermal ink transfer ribbon into and out of contact with the circumferential portion of the printing drum. An electronic postage meter having a thermal postage printing mechanism for the printing of postage indicia and postal values in a respective fixed and variable format, said thermal postage printing mechanism comprising: means for defining a postage tape feed path (40); means (21, 39, 41) for dispensing lengths of postage tape along said feed path; a first thermal printing station (20) disposed along said feed path for printing said fixed indicia upon said tape and including a heat source (34) and a rotatable printing drum (27) substantially surrounding said heat source and supporting a screen (33) around a circumferential portion of the drum and containing said fixed indicia; a second thermal printing station (30) disposed adjacent said first thermal printing station (20) for printing variable postage information upon said postage tape, said second thermal printing station (30) including thermal heating elements responsive to voltage pulses initiated by electronic signals related to a postage value; means (22) for dispensing a thermal ink transfer ribbon (23) between said first and second thermal printing stations and said postage tape to travel in conjunction with said tape along the tape feed path past the first and second printing stations, whereby ink from the ink transfer ribbon can be transferred to said postage tape by each of said first and second thermal printing stations operable in sequence and in electrical and mechanical registration with each other to form a composite postage print on said tape; and an idler belt (31) carried by rollers (26,32,38) to provide support for said tape and said thermal ink transfer ribbon to carry said tape and said thermal ink transfer ribbon into and out of contact with the circumferential portion of the printing drum. An electronic postage meter according to Claim 2, wherein said postage tape dispensing means (21,39,41) is capable of dispensing two different lengths of postage tape. An electronic postage meter according to Claim 2 or 3, wherein said heat source includes a flash lamp. An electronic postage meter according to Claim 4, wherein said printing drum comprises means for receiving an additional screen for printing a slogan upon said postage tape. An electronic postage meter according to any one of Claims 2 to 5, further comprising a microprocessor (14) for initiating said voltage pulses for said second thermal printing station (30). An electronic postage meter according to Claim 6 further comprising a keyboard (11) for selecting postage, said keyboard being electrically connected to said microprocessor (14) for supplying electronic signals to initiate said voltage pulses. An electronic postage meter according to Claim 7 further comprising a display (12) electrically connected to said keyboard (11) for displaying selected postal values. An electronic postage meter further according to any one of Claims 2 to 8, further comprising cuffing means (39) disposed along said feed path (40) for cutting a given length from said postage tape. An electronic postage meter according to Claim 9, wherein said cutting means is disposed along said feed path upstream from said first and second thermal printing stations. An electronic postage meter according to Claim 10 as dependent on claim 3 wherein said cutting means has the capability of cuffing said postage tape into different lengths.

Inventors: CALVI SALVATORES J, CALVI, SALVATORES J.
Applicants: PITNEY BOWES INC, PITNEY BOWES INC.
Application year: 1985
Main classification: G07B17
IPC codes: B41J2, G07B17, B41J29, G06K15, H04N1