Ink jet postage printing apparatus

Abstract

A postage printing machine is described wherein postage indicia are formed with an electronically controlled ink jet printing device. A rotating drum carrying a conventiona die printing plate is moved past the ink jet printing device, the latter being adapted to be actuated in predetermined sequence to project droplets of ink through apertures formed in the die plate and onto an envelope, label or other document on which postage markings are to be made.

Description

FIELD OF THE INVENTION

This invention relates to postage printing. More specifically the invention relates to a postage meter in which is incorporated an electronically controlled ink jet printing device whose operation is adapted to be coordinated with the operation of other devices in the meter.

BACKGROUND OF THE INVENTION

Postage meters are well-known in the art and commonly include selectively operable alpha-numeric printing means for printing postal indicia on envelopes or the like. Typically two types of printing means are employed; one being a die plate that is adapted to print fixed information such as the town and state, while the other is a settable printing means which is adapted to print variable information such as date and postage amount. The variable printing means usually includes print wheels which project through suitable apertures formed in a curved die plate carried on the periphery of a drum. When the drum is rotated the printing die plate and the print wheels are suitably inked so as to be capable of imprinting on an envelope a composite postage marking.

In order to vary the postage amount and the date a keyboard or similar setting means is normally provided to selectively vary the operative positions of the print wheels which are mounted to bodily rotate with the said drum. The setting linkage between the print wheels and the keyboard necessitates a rather intricate and mechanically complex arrangement in order that said print wheels may be first variably set to selected rotary positions from the keyboard and then be bodily swung through a rotary printing path determined by the movement of said printing drum.

SUMMARY OF THE INVENTION

In an improved postage meter in accordance with the invention, the variable printing wheels and the associated setting linkages are dispensed with and replaced with an electronically controlled and actuated ink jet printing device. As described with reference to a preferred embodiment of the instant, invention, a drum carries an apertured printing die plate that is adapted to cooperate with a stationary ink jet printing device to produce a postage imprint. When a date aperture and a postage amount aperture in the die plate pass below the ink jet printing device, a plurality of ink droplets are sequentially ejected through the apertures and onto an envelope or label located at the meter print station. An electronic control is provided to actuate the ink jet printing device in timed relation to the movement of said die plate to form the required number and placement of said ink dots on the envelope to thereby establish the desired date and/or postage amount indicia. A drum position sensor is used to determine when said die plate apertures are properly aligned with the ink jet printing device and the postage receiving portion of an envelope or label; a print signal then being generated by the sensor and applied to the electronic control to initiate and sequence the ejection of the ink droplets.

By incorporating a jet printing device in the postage meter the structural arrangement of the meter can be greatly simplified, and the mechanical complexity reduced to the point whereby a relatively simple efficient electronically controlled postage printing machine is made possible. Further if desired all the parts of postage markings may be produced by the electronically controlled jet printing means to even further reduce the mechanical elements required in the machine.

It is therefore an object of the invention to provide an efficient electronically controlled postage printing device having fewer parts and being capable of operating at higher cyclic printing speed, and with greater flexibility of control.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the instant improved postage printing device may be understood from the following description of a preferred embodiment as illustrated in connection with the drawings wherein;

FIG. 1 is a perspective partially schematic representation of a pertinent portion of a postage printing device with its ink printing means and controls arranged in accordance with the invention;

FIG. 2 is a side elevational view in partial section and illustrates the arrangement of the postage printing device shown in FIG. 1; and

FIG. 3 is a schematic representation of the control elements employed with the postage printing device in accordance with the instant invention.

DETAILED DESCRIPTION OF EMBODIMENT

Except as otherwise provided herein the instant postage meter apparatus may be constructed and arranged in a manner similar to that of presently known postage meters and associated apparatus. The following description is general in nature as respects the meter controls in that such are significant only to the extend that they illustrate the cooperation between the instant jet printers with the remaining printing means of the instant meter.

With reference to FIGS. 1 and 2, some of the components of a postage meter 10 having a postage printing device 11 in accordance with the invention are shown with an envelope 12 being illustrated in transit through the print station of postage meter 10. A printing drum 16 is secured to a shaft 18 that is adapted to be rotatably driven by a motor 20. Shaft 18 is journaled in a suitable bearing 22, FIG. 2, mounted on the machine frame 23 and is adapted to rotate drum 16 in the direction shown by arrow 24, FIG. 1. Drum 16 carries an arcuate die printing plate 26 which is provided with printing elements such as 28, 30 that are operative to print the fixed or non-varying postal indicia illustrated in the postage marked region 32 of envelope 12, FIG. 1. A spring biased swingable impression roller 34 supported in a coventional manner on the machine frame is located below the lower peripheral portion of drum 16 to assure operative contact of the envelope with the drum 16 as the latter rotates in printing contact with the envelope 12. Envelope 12 is slidably supported on an envelope support plate 35 having a suitable opening 36, FIG. 1, that enables the impression roller 34 to contact the envelope 12.

The printing die plate 26 has a pair of circumferentially spaced apertures or windows 37, 38 that are adapted to permit a stationary ink jet printing device 40 to project ink droplets therethrough and onto the envelope 12. Leading aperture 37 allows passage of the postage amount forming ink droplets from device 40 to envelope 12, while the trailing window 38 allows the date forming droplets from device 40 to reach said envelope. The ink jet printing device 40 is at least partially disposed in an enlarged axially extending recess 42 formed in the end of drum 16, the jet printing device being stationarily positioned in said recess so as to enable apertures 37, 38 to pass adjacent the lower ink nozzle end 44 thereof and to thus permit and prevent passage of ink droplets to said envelope.

The ink jet printing device 40 is formed with a plurality of precisely aligned and closely spaced ink-conducting capillaries or channels 46 whose respective ends 43 are arranged in a linear array at said lower end 44 of the printer as is illustrated in FIGS. 2 and 3. The capillaries are selectively actuated to generate the proper number and sequence of ink droplets to form the alpha-numeric postage characters on the envelope. The general construction and operation of this type of ink jet printing device may be similar to that presently produced and sold by Gould, Inc. of Chicago, Ill. and hence such needs no detailed description here. Suffice it to indicate that a piezo-electric crystal 48 is located in communication with each of the capillary channels 46. When a crystal is energized by an electrical pulse, a slight physical deflection thereof is produced which is sufficient to cause ejection of tiny ink drops through the end 43 of the associated channel 46. These piezo-electric crystals 48 may be located on both sides of the ink jet printing element 40 so that the ends 43 of said channels 46 may be closely spaced along a channel end center line 49, FIG. 3.

The ink jet printing device 40 is mounted on the machine frame by means of a bracket 50, FIG. 1, which carries suitable electrical control leads 52 to the individual piezo-electric elements 48. In FIGS. 1 and 2 five crystals 48 are shown mounted on the visible side of jet printing device 40 with four others (not shown) being mounted on the other side thereof. The channels 46 terminate at the machine printing station 51, FIG. 1, disposed generally below the said lower end 44 of the ink jet printing device 40. An ink supply tube 56, FIG. 1, is supported by bracket 50 and is in ink-supplying communication with said ink capillaries 46. The ink jet printing device 40 is disposed such that the ink droplets ejected from the channel ends 43 are projected radially away from rotational axis 53 of drum 16 and downwardly towards the envelope 12 along a vertical plane which includes the drum axis 53 and said center line 49. Although the plane of the end 44 of the jet printing device 40 is actually substantially normal to the plane of drum 16 as shown in FIG. 1, the said plane of the end 44 of the printing device is, for ease of description, shown in FIG. 3 as being substantially parallel with the plane of said drum 11.

The rotation of shaft 18 is sensed by operation of a drum position sensor 56 that causes the ink jet printing device to be actuated in timed relation to the rotation of the print drum 16. Although an optical type position sensor is illustrated here it will be apparent that other conventional types of rotational position sensing means such as magnetic devices etc. may be alternately used. The sensor 56 includes a timing disc 58 that is secured to shaft 18; the disc being provided with a pair of rotational position indicating apertures or slots 60, 62. Sensor 56 also includes a conventional type photo detector 64 which is operatively aligned with a light source 66. As will be apparent a signal will be generated at the sensor output line 68 when each disc slot 60, 62 swings between the source 66 and the detector 64. The peripheral locations of the slots are arranged so that said output signals at line 68 occur when the drum apertures 37, 38 respectively move below the lower end 44 of the ink jet printing device 40.

The apertured outer cylindrical walls of drum 16 effectively constitute a movable masking member which prevents ink from reaching envelope 12 when neither of the apertures 37 or 38 is located between the ink jet printing device 40 and the envelope 12. In this way the said cylindrical walls of said drum 16 serve as a security means for the meter and prevents spurious printing of postage indicia at any time other than the prescribed time during a valid meter cycle of operation. As is shown in FIG. 3 the outer cylindrical wall of the drum is formed with apertures which register with apertures 37, 38 when the die plate 26 is secured to the drum 16.

Any suitable electrical control means may be used to produce the synchronization between rotation of the print drum 16 and the sequence pulse actuation of the jet printer 40. An exemplary type of control is generally illustrated in FIG. 1 wherein the output print signal on line 68 is applied to a timing amplifier 70 whose output line 72 drives a logic network 74. The latter network enables present keyboard 76 signals to be applied to a matrix character generator network 78 and a meter memory 80. The output from the actuation of a keyboard and/or other setting means for producing variable date and postage amount information is permitted to pass by logic network 74 to the matrix 78; the latter then generating a proper conversion of the keyboard data to a coding compatible with the nine ink-dot producing channels 46. Thus, matrix 78 determines both which piezo-electric cyrstals are to be activated as well as the sequencing actuations thereof needed to produce the keyboard set postage characters. When the logic network 74 is activated by a print signal on line 72, the keyboard data is stored in permanent meter memory 80. In addition an interlock signal is produced on line 82 to a clutch interlock 84 coupled to motor 20. The clutch interlock assures that the machine printing cycle will be completed once it has been initiated. Timing disc 58 further is associated with a suitable cycle terminating device 86, FIG. 3, which is coupled to motor 20 so as to terminate the rotation of drum 16 at a desired home position. The cycle terminating device 86 includes a magnetic flux element 88 mounted on the perimeter of the timing disc 58 and a magnetic sensor 90 which is closely spaced from the timing disc 58 and which is adapted to sense the passage of the flux element 88 thereby. The position of sensor 90 is so chosen that when it senses the passage of flux element 88, the first aperture 37 is located approximately at a home position indicated in FIG. 3 by the line 37a, the then relative operative position of the jet postage printing device 40 here being indicated by line 40a in FIG. 3. When sensor 90 has detected the passage of flux element 88, a signal is applied on lines 94--94' to an amplifier 96 whose output 98 is coupled to a suitable electromagnetic relay 99 to terminate the rotational drive from motor 20.

The operation of the postage meter 10 is commenced after the envelope 12 is inserted from the left, as seen in FIG. 1, to a position such that its leading edge 100 is initially located approximately in the plane of centers of drum 16 and the impression roll 34. The keyboard and/or other setting control means for the variable amount and data date to be printed is then operated and the usual machine, trip or cycle initiating means (not shown) is actuated to initiate operation of motor 20. The drum 16 being thus driven the die printing plate 26 is initially brought into contact with a suitable inking roller 102, the latter being provided in the usual manner with ink from transfer rollers 104 and 106 which are coupled to an ink supply (not shown). When the die plate 26 thereafter contacts envelope 12 the latter will be gripped between the radially extended peripheral portion of the plate 26 and the cooperating impression roll 34 so as to be longitudinally fed to the right, as seen in FIG. 1, as the drum 16 is driven in a counter-clockwise direction as indicated by arrow 24 of FIG. 1. During this longitudinal movement of the envelope the inked printing die plate will progressively roll print the said fixed postal indicia 28, 30 etc. onto the envelope. At the same time the variable postage amount and date indicia will be successively printed by the jet printer 40 as the windows 37 and 38 respectively swing past the print station 51 whereby a complete composite postal marking is thereby produced on the envelope 12, the timing for printing of these variable indicia being under the control of disc sensor 56. Here when the first aperture 37 arrives in alignment between the ink jet printing element 40 and envelope 12, a print signal from sensor 56 (corresponding to disc notch 60) is produced on line 68. This results in the operation of the jet printer to print the postal amount that has been set on the keyboard or other input control. When the next aperture 38 arrives between ink jet printing device 40 and envelope 12, another print signal is produced by sensor 56 (corresponding to disc notch 62) and this print signal will cause the matrix 78 to control the pulse actuation of jet printer so that the date indicia is printed on the envelope. After the completion of the postage printing action during one revolution of the drum 16 the machine cycle will be terminated by action of said terminating device 86 so that said aperture 37 is again in its said home position 37a.

The above described postage meter arrangement being essentially electrically controlled as respects printing of the variable indicia allows the many complex mechanical linkages normally associated with postage meters to be eliminated. Also this arrangement allows the meter to be coupled to and/or incorporated in various types of electrical control devices or systems. The embodiment described above illustrates the formation of a postage marking using both a conventional die plate and the ink jet printing device, however the ink jet printing device may be used to form the entire postage marking. As will be evident, the postage indicia may be printed on a label instead of on an envelope, the printed label then being secured to a package or other item to be mailed.

For the purpose of clarity many of the conventional mechanical safety and security features normally included in postage meters are not described herein, however these form no part of the instant invention and hence need not be discussed here. As previously mentioned the controls for the drum motor 20 and the jet printer 40 are described above in only a general way in that they are intended merely to typify and suitable control means that may be used to obtain the above described interrelation of operation of the printing drum 16 and the ink jet printer 40.

Claims

What is claimed is:

1. In a postage meter having a printing station and a means for supporting at said printing station a document such as an envelope, label or the like that is to have postage indicia printed thereon;

a first printing means for printing fixed information of said postage indicia such as the city and state;

a second printing means for printing variable information of said indicia such as the postage amount;

said second printing means consisting of an ink jet printing device that is adapted to project ink droplets onto said document so as to form said variable information of said postage indicia; and

security means adapted to prevent the effective operation of said jet printing device during at least a portion of the operation of said first printing means and to permit the effective operation of said jet printing device only during a limited period of time, said limited period of time being less than the period of time during which said first printing means is operative.

2. Apparatus as defined by claim 1 wherein said security means includes a masking member movably mounted in said meter and when in a first operative position being adapted to permit said ink droplets to reach said document and when in a second operative position being adapted to prevent said ink droplets from reaching said document.

3. Apparatus as defined by claim 1 wherein said first printing means includes a die plate carried by a drum that is rotatably mounted in said meter; wherein at least a portion of said jet printing device is mounted within said drum; and wherein said die plate and the peripheral walls of said printing drum are provided with mutually registering apertures which permit said ink droplets to reach said document when said apertures are respectively located in a position between said jet printing device and said document; and wherein said security means includes an unapertured portion of said peripheral walls which when said apertures are not located between said jet printing device and said document prevent any of said ink droplets from reaching said document.

4. In a postage meter:

a printing station;

means for supporting at said station a document such as an envelope, label or the like that is to have postage indicia printed thereon;

an ink jet printing device adapted to project a predetermined sequence of ink droplets onto said document so as to thereby define at least a portion of said postage indicia;

security means mounted in said meter for movement through the region between said document and said ink jet printing device;

said security means including a movable member having a wall that is formed with at least one aperture therethrough, the remaining portion of said postage indicia being adapted to be printed by means carried by the side of said wall remote from said ink jet printing device;

said member when in a position where said aperture is operatively disposed between said jet printing device and said document permitting passage of said ink droplets onto said document, and when in a position where said aperture is not disposed between said jet printing device and said document preventing passage of said ink droplets onto said document.

5. Apparatus as defined by claim 4 wherein said member is defined by a peripheral portion of a drum that is rotatably mounted in said meter.

6. Apparatus as defined by claim 4 wherein said member carries a die plate that is adapted to print fixed information of said postage indicia, said die plate being formed with at least one aperture which is disposed in registration with the said aperture formed in said member.

7. In a postage meter:

a printing station;

means for supporting at said station a document such as an envelope, label or the like that is to have postage indicia printed thereon;

an ink jet printing device adapted to project a predetermined sequence of ink droplets onto said document for printing the postage amount portion of said postage indicia;

security means mounted in said meter for movement through the region between said document and said ink jet printing device;

said security means including a masking member movably mounted in said meter and when in a first operative position being adapted to permit said ink droplets to reach said document and when in a second operative position being adapted to block passage of any of said ink droplets to said document.

8. Apparatus as defined by claim 7 wherein said masking member is defined by an apertured printing drum which is rotatably mounted in said member and which carries a correspondingly apertured die plate that is adapted to print fixed information of said postage indicia.