GB2183546A

GB2183546A - Electronic postage meter

Info

Publication number: GB2183546A
Application number: GB08529425A
Authority: GB
Inventors: Ray L Bannister
Original assignee: Pitney Bowes PLC
Current assignee: Pitney Bowes PLC
Priority date: 1985-11-29
Filing date: 1985-11-29
Publication date: 1987-06-10
Also published as: GB8529425D0; EP0225068A2; EP0225068A3; JPS62156796A

Abstract

A microprocessor in an electronic postage meter is mounted in a hybrid circuit 10 together with various peripheral circuits, so that much of the control circuitry of the postage meter is essentially within the one replaceable unit. The hybrid circuit 10 may be mounted on a mother board 16 resulting in easy replacement and also leading to a very compact arrangement; whilst the hybrid circuit 10 may contain accounting devices, memories and clock generators, the board 16 connects with power supply 26. Keypad 28, solenoids for setting of the postage meter, and LCD display 30. <IMAGE>

Description

1 GB 2 183 546 A 1

SPECIFICATION

Electronic postage meter The present invention relates to an electronic pos- 70 tage meter, particula rly such a meter under the con trol of a microprocessor.

Postage meters including microprocessor control circuits are known, and such meters can theoretically be smallerthan conventional mechanical postage meters since certain functions such asvaluesetting, displayand accounting can be performed electronic ally ratherthan by means of complex mechanical lin kages. In principle, such postage meiers can also be constructed more cheaply since, assuming a suffici ently largevolume of production, electronic com ponents (even if some need to be custom-made) and their assembly should be less expensive than the complex mechanical counterparts and their 2Wassembly.

However, despite the existing use of micro processors in postage meters, it has been found in practice thatthe above-mentioned advantages have not been fully realised. One reason is thatthe assembly of peripheral components external to the microprocessor has been complex and thus expens ive; moreover once the necessary peripheral com ponents have been added, there may be little or no difference between the space requirements within the casings of this type and those of mechanical pos tage meters. Another reason is that it has been found necessaryto include morethan one microprocessor if specificfunctions areto be provided, andthis clearly involves both cost and space penalties.

Servicing of these types of control circuits has also involved disadvantages, since a circuit board carrying the microprocessor and its peripheral components would in the event of failure need to be subjected to complicated diagnostic techniques. In such cases, the service engineerwould have to remove the postage meterfrom the customer's premises in orderto carry outthe diagnostictests at hisworkshop.

In orderto overcome, or at least reduce the above- mentioned disadvantages, the present invention provides an electronic postage meter comprising:

means whereby data can befed into the meter, said data including at least numerical information relating to the valueto befranked; meansfor printing postage; microprocessor meanswithin the meterforcontrolling the printing of postage; accounting means for keeping an account of postage printed; an electronic memoryfor storing therein digital values corresponding to thetotal of postagethat has been printed; a program memory incorporating a postage meter program to enable the microprocessor means to control the operation of the meter; a clock circuitfor generating timing signals forthe microprocessor means; and circuitry connecting the aforesaid parts together; characterised in thatthe microprocessor means, the accounting means, the program memory, the el- ectronic memory, or a socket arrangementfor retaining at least the electronic memory, the clock circuit, and at least part of the interconnecting circuitry are mounted togetherto form a so-called hybrid circuit.

The hybrid circuit is preferably fabricated by a technique in which thin ceramic plates have the microprocessorand peripheral circuits mounted thereon in layers, electrical connections between these components being made during the hybridisa- tion process, pins being provided for electrical connection to circuits outside the hybrid circuit.

In one embodiment, all the circuits of the postage meterwhich would normally be provided on a control circuit printed circuit board can be arranged within the hybrid circuit. Thus in the event of a malfunction,the service engineer merely needsto replacethefaulty hybrid circuitwith another, andthere is no need forthe postage meterto be removedfrom the customer's premises.

in another embodiment, the hybrid circuit has mounted thereon a socket for receiving the microprocessor or at least a non-volatile memory storing the cumulative total of postage printed. In the event of failure of other parts of the hybrid circuit,the memorycomponent can be unplugged from the socket and its stored data unloaded for recording and subsequent inputting to a replacement component.

The hybrid circuit may be mounted asthe sole el- ectronic component on a mother board; alternatively, switching devices such asfield effecttransistors (FETs) for activating external solenoids of the postage meter can also be mounted on the mother board.

The use of such a hybrid circuit leads to a significant space reduction, thereby making it possibleto design a more compact postage meter.

Furthermore, the incorporation of all or most of the components within the hybrid circuit leads to a more rugged construction, since the circuit is much less vulnerable to effects such as vibration.

The invention will now be further described, by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which:

Figure 1 shows a partially-schematic perspective view of the assembly of the electronic parts of a postage meter in accordance with an embodiment of this invention; and Figure2 is a circuit diagram of the electronic parts of a postage meter, which circuit can be used inthe assembly of Figure 1.

Referring to Figure 1, electronic components of a postage meter include a hybridised control circuit 10 with conductive pins 12for mounting within aper- tures 14 of a mother board 16 and for electrical connection theretojor example by soldering. Details of the components within the hybrid circuit 10 will be given below in connection with Figure 2, but atthis stage it is sufficientto saythatthe hybrid circuit 10 includes a microprocessor and its peripheral circuits, preferably mounted on ceramic plates, layer by layer, with interconnections being made between the parts by conventional hybridisation techniques.

The mother board 16 preferably carries justthe hybrid circuit 10 and input/output connectors such 2 GB 2 183 546 A 2 as a power supply connector 18, a mem bra nekeypad connector 20, a solenoid connector 22 and a display connector 24. Connection between the hybrid circuit and these connectors can be achieved by any suit able conventional means, such as conductive tracks underneath the mother board 16. The mother board 16 can be connected to external parts such as a power supply and filters 26, a membrane keypad 28, solenoids (not shown) and LCID display device 30 via the appropriate connectors and ribbon cable. The connectors can be in the form of IDC (insulation dis placement connection) headers which are part icularly suitablefor use with ribbon cable.

In one arrangement, switching devices forthe sol enoids, such as field effect transistors (FETs), can be included within the hybrid circuit 10; in another arrangement, the FETs are instead mounted on the mother board.

It wil 1 therefore be seen f rom Figure 1 that if there is a malfunction within the hybrid circuit 10, repair 85 can be effected simply by unplugging the various connectors and removing the complete mother board 16 with its hybrid circuit 10. A new unitcan be inserted as a replacement, and if required, servicing can be carried out on the faulty circuitsubsequently attheworkshop.

In an alternative arrangement, the hybrid circuit 10 can include a socket mounted thereon, the socket being arranged to carry at least a non-volatile memory component of the control circuit. in the event of a circuit malfunction elsewhere within the hybrid circuit,the memory component can be un plugged and its data unloaded so as to preserve the cumulative accounting information.

It will be seen from Figure 1 thatthe arrangement is extremely compact and takes up a small amountof space within the casing of a postage meter.

Figure2 shows a circuit diagram of a postage meter control circuit, parts of which can be included within the hybrid circuit 10 of Figure 1.

Referring to Figure 2, the main component of the circuit is a microcontroller 40, shown as a Motorola MC68HCl 1A8 device. This is a particularly powerful HCMOS (high-density high-performance silicon gate) 8-bit device, including, aswell asthe processor, 8K bytes of ROM, 512 bytes of EEPROM and 256 bytes of static RAM. The microcontroller 40 is connected to the powersupply and filter 26 (onlythe filter part being shown in Figure 2), to the membrane keypad 28 via four signal diodes 42,to the solenoids via four inverting buffers 44 (in association with four puli-up resistors 46) and via appropriate switching FETs (not shown), and to the LCID display device 30. The remaining circuits shown in Figure 2 (that is otherthan the power supply 26, keypad 28, solenoids and LCD display device 30), including logiccircuits and a 4MHz crystal oscillator48 providing clock or timing signals forthe microcontroller, form part of the hybrid circuit 10 and, as previously mentioned, are mounted with the microcontroHer40 in a layer structure on ceramic plates. A preferred arrangement, however, is forthe microcontroller 40 to be removable from the hybrid circuit 10. Forthis purpose, an integrated circuittype socket can be incorporated in the circuit 10 during hybridisation and the micro- controller 40 simply plugged in. The advantage of this arrangement is that should there be a malfunction of any other circuit within the hybrid circuit 10, the microcontroller40 can be unplugged and the re- levant data, including the cumulative accounting data, can be unloaded for records purposes and for subsequent entry into a replacement component.

Operation of the circuit is conventional, postage valuesto be printed being input by means of the membrane keypad 28. The appropriate data isthen fed to the microcontroller40 along the matrix lines fromthe keypad 28. The postagevalue information is displayed on the LCD display device 30 and the appropriate accounting operations are performed bythe microcontroller40 in known manner, which also controls the solenoids associated with the electromechanical parts of the postage meter, such as the printing head. The operation can be broadly similar to that described in UK Patent No. 2 062 312.

The use of a powerful microprocessor such asthe MC68HCl 1A8 permits current account mode operation, aswell as maintaining the usual ascending and descending accounts. Also, a batch accountcapability can be provided, as well as automatic date change if required.

if a less powerful microprocessor is used, it may be necessaryto provide a separate non-volatile memory for storing cumulative accounting data. In thatcase, the non-volatile memory could be remov- ably mounted with the hybrid circuit 10 using a socket arrangement similarto that described above.

Although as shown in Figure 2, the powersupply 26 is shown external to the hybrid circuit 10, parts of the powersupply 26 could be incorporated within the hybrid circuit. In particular,the voltage regulator (referenced by its type number7805) and associated filter resistor/capacitor components could be hybridised within the circuit 10 as long as the regulated supplywas onlyfed to the microcontrollerand associated components. The relatively heavy current requirements of the solenoids would then be metdirectlyfrom the uregulated supply.

Acomparison of the circuitcliagram of Figure 2 with the assembly drawing of Figure 1 should make apparent how much space can be saved by providing all possible circuit functions within the hybrid circuit 10, ratherthan providing these as discrete circuits on the board 12.

Claims

1. An electronic postage meter comprising: means whereby data can be fed into the meter, said data including at least numerical information relating to the valueto befranked; means for printing postage; microprocessor meanswithin the meterfor controlling the printing of postage; accounting means for keeping an account of pos- tage printed; an electronic memory for storing therein digital values corresponding to the total of postagethat has been printed; a program memory incorporating a postage meter program to enable the microprocessor meansto 3 GB 2 183 546 A 3 d 10 control the operation of the meter; a clock circuitfor generating timing signals forthe microprocessor means; and circuitry connecting the aforesaid parts together; characterised in that the microprocessor means, the accounting means, the program memory, the electronic memory, or a socket arrangementfor retaining at least the electronic memory, the clock circuit, and at least part of the interconnecting circuitry are mounted togetherto form a so- called hybrid circuit.

2. A postage meter according to claim 1, wherein the microprocessor means, the accounting means and the program memory are constituted by a single integrated circuit component mounted in the hybrid circuit.

3. A postage meter according to claim 2, wherein the integrated circuit component is a microcontroller also including the electronic memory in the form of a non-volatile memory.

4. A postage meter according to claim 2 or claim 3, wherein the hybrid circuit includes a socket for receiving the integrated circuit component.

5. A pbstage meter according to anyone of the preceding claims, wherein the microprocessor means and other components of the hybrid circuit are mounted on ceramic plates and interconnections are made therebetween during the hybridisation process.

6. A postage meter according to anyone of the preceding claims, wherein the hybrid circuit is mounted on a mother board as the sole component apart from connection means for external devices.

7. A postage meter according to anyone of the preceding claims, wherein switching devices forthe printing means and for other external devices are provided in the hybrid circuit.

8. A postage meter according to anyone of claim 1 to 5, wherein the hybrid circuit is mounted on a mother board as the sole component apartfrom connection means for external devices and apart from switching devices forthe printing means and for other external devices.

9. A postage meter according to anyone of the preceding claims, wherein logic circuits are provided in the hybrid circuit.

10. A postage meter according to anyone of the preceding claims, wherein the clock circuit comprises a crystal controlled oscillator in the hybrid circuit.

11. A postage meter according to anyone of the preceding claims, wherein a voltage regulator for the other components in the hybrid circuit is also prov ided in the hybrid circuit.

12. An electronic postage meter substantially as herein described with reference to and as illustrated in the accompanying drawings.

13. Each and every novel combination and/or sub-combination described and/or illustrated herein.

Printed for Her Majesty's Stationery Office by Croydon Printing Company (UK) Ltd,4187, D8991685. Published byThe Patent Office, 25Southampton Buildings, London, WC2A l AY, from which copies maybe obtained.