Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ELECTRONIC POST~GE METE~ PRINT W~EEL SETTING
OPTIMIZATION SYSTEM
FIELD OF THE INVENTION
The present invention relates to electronic postage
meter value selection setting systems, and more par-
ticularly, a system for optimizing the setting speed of
the postage printing value selection mechanism.
BACKGROUND OF THE INVENTION
Postage meters are mass produced devices for
imprinting a defined unit value for governmental or
private carrier delivery of parcels and envelopes. The
term "postage meter" also includes other like devices
which provide unit value printing such as tax stamp
meters. Postage meters include internal accounting
devices which account for postage value representation
which is stored within the meter and is printed by the
meter. The postage printed by the meter is adjustable or
settable through a value selection system to any value,
within a range of values, selected by the postage meter
user. The accounting for postage printed by the meter is
stored only within the meter. As a result, postage
meters must possess an extremely high reliability to
avoid the loss of user or governmental funds stored
within the meter.
Postage meters are often used in systems wherein
the mail piece which i5 to receive a postage stamp
impression, is transported to the postage meter ~or
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imprinting. Systems of this type have been proposed
which are coupled to scales to weigh the mail piece to
determine the appropriate postage. The scale mechanism
in such systems may be connected to the postage meter to
cause the postage meter value selection mechanism to
operate to set the postage meter print elements to the
appropriate postage for the weight of the mail piece
weighed and to be transported to the postage meter.
It has been recognized that electronic postage
meters are particularly suited for systems applications,
such as the system described above. This is, in part,
because electronic postage meters are adapted to be
electronically interfaced with scale mechanisms so that
the value selection mechanism of the postage meter can be
controlled by a signal generated by the weighing device
and coupled to an input port of the electronic postage
meter.
Examples of electronic postage meters are dis-
closed in U.S. Patent No. 3,938,095 for COMPUTER RESPON-
SIVE POSTAGE METER; U.S. Patent No. 3,97~,457 for MICRO-
COMPUTERIZED ELECTRONIC POSTAGE METER SYSTEM; and, in
U.S. Patent No. 4,301,507 for ELECTRONIC POSTAGE METER
HAVING PLURAL COMPUTING SYSTEMS. In postage meters
of the type disclosed in the noted U.S. Patents, the
accounting mechanism and the value selection mechanism
are electronically controlle~. The memory function in
the electronic accounting circuits have replaced the
~unction served in mechanical postage meters by mecha-
~ ;~s~;~Q3--3--
nical accounting registers. The motor or solenoid
operated, electronically controlled, setting mechanism
have replaced the function served in mechanical postage
meters by levers and thumbwheels. Both the accounting
circuits and value selection system in such postage
meters may be operated under microcomputer control.
The value selection system must operate accurately
in adjusting the postage meter printing mechanism to an
appropriate selected postage value to be imprinted. An
error in the value selection mechanism could result in a
loss of funds to either the user or government. Addi-
tionally, such an error could result in a mail piece
being imprinted with a deficiency in the postage stamp
value such that the governmental or private carrier will
refuse or delay delivery of the parcels and envelopes,
and/or, require additional postage to be paid over the
amount printed on the mail piece, by either the sender or
recipient.
In systems applications, it is desireable to
increase the number of mail pieces which are imprinted
with a postage stamp within a given unit of time without
sacrificing the accuracy and reliability of the meter
including the meter setting mechanism. By increasing the
throughput, the productivity of the postage meter system
is enhanced, diminishing the unit handling cost to the
postage meter user of each mail piece. Nevertheless,
because post~ge meters print unit value and are accounted
for by no other mechanism than the postage meter account-
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ing registers, the value set in the print mechanism mustaccurately reflect the value intended.
In recognition of the criticality of the postage
value selection function, postage value selection confir-
mation systems have been incorporated in the electronicpostage meter systems disclosed in U.S. Patent ~o.
3,938,095 and U.S. Patent No. 3,978,457.
SUMMARY OF THE INVENTION
The present invention optimizes the speed of the
value selection mechanism in a postage meter. It is also
believed that the system of the present invention will
allow the specification for meter operating mechanism
components which are less rigorous, thereby resulting in
reduced cost, for mass produced postage meters. This is
because of the self adjusting feature of the setting
mechanism when setting errors are detected. Thus, for a
mass produced postage meter, significant savings may
result by allowing the purchase of less expensive
components
It has been discovered that the value selection
mechanism speed in a postage meter can be maximized by
controlling the postage meter such that each time the
postage meter is energized, the meter setting mechanism
i5 controlled to increase the setting speed for each new
setting until an error is detected. At this point, the
postage meter setting mechanism controller readjusts the
setting speed to a lower speed where an error is not
encountered. The operation of the postage setting
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mechanism then is operated for the duration of the meter
use at the highest possible setting speed where no error
is encountered.
It has been discovered that the speed with which
postage value is set in a postage meter will become more
and more important as the throughput of mail handling
systems is increased. In systems where the postage to be
printed on a mail piece is automatically determined, for
example, by weighing on an electronic scale or by compu-
tation knowing the contents of the mail piece, andcommunicated electronically to a postage meter, the
postage setting time may require the whole system to slow
down or stop until the meter is ready to imprint the
postage value on the mail piece. This is particularly
important in mixed weight mail mailing systems applica-
tions where the meter print elements are frequently
changed for imprinting the proper postage value on each
mail piece passing through the system. It is therefore
desire~ble to increase the setting speed to avoid such
delays.
In a postage meter system embodying the present
invention postage printing means are provided with
settable postage printing elements. Drive means are
coupled to the postage printing means for setting the
postage printing means settable postage printing ele-
ments. The drive means are operable to drive the postage
prlnting means settable postage printing elements at
different operating speeds to set the postage printing
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elements to selected postage value to be printed.
Control means are coupled to the drive means for con-
trolling the drive means to set the postage means set-
table postage printing elements to the selected postage
value and for controlling the speed of operation with
which the drive means drives the postage printing
means settable postage printing elements to the selected
postage value to be printed. Error detecting means are
coupled between postage value selection input means and
the postage printing mechanism and are further coupled to
the control means, for detecting errors ~etween the
selected postage value entered into the postage value
selection input means and the actual setting of the
postage printing means settable postage printing element
setting and providing error information to the control
means. The control means are operable in response to
print element settinq error information to control the
speed with which the drive means operates to drive the
postage printing means settable postage printing elements
to a selected postage value.
The present invention ~urther embodies the method of
increasing the setting speed of ~he value selection
mechanism of a postage printing device, detecting whether
the setting at each speed results in a proper setting of
the print elements of the postage printing device to the
value intended and reducing the setting speed of the
value selection mechanism of the postage printing device
when predetermined setting error information is detected.
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Other aspects of this invention are as follows:
In a postage meter system of the type having postage
value input selection means ~or specifying a desired
postage value, a postage printing means with a settable
printing element and a drive means in co~nunication with
said input selection means and coupled to said postage
printing means for setting said postage printing element
of said postage printing means, a print element setting
system, comprising:
said drive means operable to drive said printing
element of said postage printing means at different
operating speeds to set said postage printing element to
selected postage value;
position detecting means for detecting the actual
position setting of said printing element; and
control means coupied to said input selection means
and said drive means ~or controllably causing said drive
means to change the position of said postage printing
element from an initial position to a selected position
corresponding to the desired postage value specified by
said input selection means at a given setting speed and
incrementally increasing said setting speed for each
successive position change o~ said postage printing
element up to a maximum setting speed;
said control means further coupled to said position
detection means for comparing the actual position o~ said
postage printing element to the selected position by said
input selection means such that should said selected
position and said actual position of said postage printing
elements not correspond said control means shall position
correct said postage p~inting element to said selected
position and decrement said setting speed and set said
maximum setting thereto.
In a postage meter system o~ the type having postage
value for s~lection means for specifying a desired postage
value, a postage printing means with a settablP printing
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element and a stepper motor coupled to said postage
printing means for setting said pos-tage printing element
of said postage printing means, a print element setting
system, comprising:
said stepper motor operable to dri~e said postage
printing means settable printing element at different
operating speeds to set said postage printing element to
selected postage values;
position detection means for detecting the actual
position setting said printing element; and
microcomputer control means coupled to said input
selection means and said stepper motor for controllably
causing said stepper motor to change the position of said
postage printing element from an initial position to a
selected position corresponding to the desired postage
value specified by said input selection means at a given
setting speed and incrementally increasing said setting
speed for each successive position change of said postaye
printing element up to a maximum setting speed; and
said microcomputer control means further coupled to
said position detection means for comparing the actual
position of said postage printing element to the selected
position by said input sele~tion means such t~at should
said selected position and said actual position of said
postage printing elements not correspond said control
means shall position correct said postage printing element
to said selected position and decrement said setting speed
and ~et said maximum setting thereto.
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BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention
may be obtained from the following description of the
preferred embodiment thereof, when taken in conjunction
with the accompanying drawings, wherein like reference
numerals designate similar elements in the various
figures, and in which:
FIGURE 1 iS a block diagram of a postage meter
system adapted to embody the present invention;
FIGURE 2 is a block diagram of a portion of the
electronic system of a postage meter system and a per-
spective view, partially broken away, of a portion of the
postage printing system of the postage meter system,
embodying the present invention;
FIGURE 3 is an alternate embodiment of the postage
meter system shown in FIGURE 2 with the postage setting
drive motor external to the postage meter secure protec-
tive housing~
FIGVRE 4 is a flow chart of the operation of the
postage meter system program for operating the postage
meter system shown in FIGURES 2 and 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to FIGURE 1. A postage meter
system 10 includes an electronic postal scale 12 and an
electronic postage meter 14. A communications bus 16 is
connected between the electronic postal scale 12 and the
electronic postage meter 14 for conveying information
regarding the postage value required for a mail piece,
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such as mail piece 18 weighed by the scale in anticipa-
tion of having a postage stamp printed thereon by elec-
tronic postage meter 1~.
The mail piece may be transported by a series of
drive belts 20 and 22 to position the mail piece with
respect to the electronic meter so that a postage value
can be printed. The drive belt 22 may be part of a
postage meter base 24 which is adapted to operate in
conjunction with the electronic postage meter 14 such as
by providing mechanical drive energy to drive the postage
printing mechanism. A data bus 26 is provided between
the electronic postage meter 14 and the postage meter
base 24 for conveying status information regarding the
operation of the electronic postage meter and the
operation of the postage meter base 24. This information
may be used to control the speed of the transport 20 and
22 to control the speed at which the mail pieces are
transported from the postal scale 12 to the electronic
postage meter 14. In this regard~ a further data bus 28
~0 may be provided for communicating information between
the electronic postal scale 12 and the postage meter base
24. Additionally, if desired, the data bus 16 may be a
bi-directional data bus, such as the data busses 26 and
28.
The electronic postage meter shown in FIGURE 1 may
be similar to the electronic postage meter shown in the
aforementioned U S. Patent No. 4,301,507 for ELECTRONIC
PO5TAGE MF,TER ~VING A PLURAL COMPUTING SYSTEMS, and the
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printing mechanism may be similar to the postage printing
system disclosed in U.S. Patent 4,287,825 for PRINTING
CONTROL SYSTEMS a system for weighing a mail piece while
in motion is disclosed in U.S. Patent No. 3,890,492 for
S POSTAGE VALUE DETERMINING CONTROL CIRCUIT and also in U.S.
Patent No. 4,325,440 for METHOD AND SYSTEM FOR COMPUTING
SPECIAL FEES IN PARCEL METERING SYSTEM.
It should be recognized with FIGURE 1 that the
information communicated by the electronic postal scale
12 to the electronic postage meter 14 over bus 16 is
utili7ed to adjust the print wheels of the postage
printing mechanism to the proper value. The length of
time to properly position the print wheels for any given
setting speed for the setting mechanism relates to the
distance to be traversed by the printing elements. For
example, the length of time to rotate a printing wheel
from a one to a nine (when rotating in the direction from
one to nine) will be greater than the time necessary to
rotate the printing wheel from one to five. It should be
also recognized that the number and amount of rota-
tions can vary greatly depending on the nature of the
mail pieces which are presented to the postage meter
system 10 to be imprinted with postage. Thus, for mixed
mail of extremely light and extremely heavy mail pieces,
the postage meter print wheels may be continuously
adjusted between various values. This adjustment of the
print wheels from one value to another value can be the
limiting factor ~or the postage meter system 10.
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Reference is now made to FIGURE 2. The electronic
postage meter shown in FIGURE 2 iS operable to maximize
the postage setting speed of the printing wheels. Each
time the electronic postage meter 14 is energized, the
postage meter microcomputer 30 under control of the
operating program in the program store, read only memory
32, enters into a mode which increases the setting speed
for each setting of the print wheels 34 of the postage
printing drum 36. It should be noted that only one print
wheel and its associated drive mechanism including the
stepping motor 38 and driver 40 is shown. The system
includes an associated setting position detection system
including the amplifier comparator 42, opto-interrupter
44 and slotted disk 46 coupled via a gear 48 to setting
rack 50. The postage meter drum may include other banks
of printing wheels, associated drive mechanism and
systems to print the various denomination required for
the postage Yalue. The postage meter drum may include 3,
4 or even 5 such print wheel systems depending on the
denominations to be printed and whether fractional cents
are to be printed~
As previously noted, each time the electronic
postage meter 14 is energized, under control of the
microprocessor 30, the meter enters a mode in which the
setting speed for each new settiny is increased until an
error is detected. At this point, the ~icrocomp~ter 30
under control cf the operating program resident in the
read only memory 32 enters into an operating mode in
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which it reduces the setting speed. The setting speed is
reduced to a speed at which no setting error is detected
and is retained at that speed for the duration of the
period of time that the meter is energized.
It should be noted that this setting speed informa-
tion can be transferred into the electronic postage
meters non-volatile memory 52 to be retained when the
meter 14 is deenergized. In such case, when the meter is
powered-up again, the information can be transferred into
the microcomputer and provide the starting point for the
setting speed of the print wheels. Additionally, in
accordance with U.S. Patent No. 4,280,180 for ELECTRONIC
POSTAGE METER HAVING FIELD RESETTABLE CONTROL VALUES, the
use of the increased setting speed can be a field service
operation or alternatively a user entered feature.
In this regard, the setting speed can be permanently set
or can be varied. It may be desired to permanently set
the setting speed for use of the rneter in predetermined
systems applications and thereafter to run through the
error detecting routine only when ~he meter is used in
different applications or in different hardware systems
configurations.
In operation, when the meter is energized, external
power is applied to the electronic postage meter 14 via
input lead 54, protection circuits 56 and energy store 58
to a power supply 60. The power supply 60 is utilized to
energize ~he microcomputer 30 and other electronic
components within the meter such as the driver 40 and the
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amplifier comparator 42. The external power applied to
lead 54 is also coupled via the protection circuits 56 to
the stepper motor 38 and to the driver 40.
~n external control communications channel 62 is
provided and is connected to the data bus 16. The
communications channel is isolated by an optical isolat-
ing system 64 which is coupled to the microcomputer 30.
Setting in~ormation for the postage printing wheel 34 is
communicated to the meter over the bus 16 from the
electronic postage scale 12. This information is used by
the microcomputer 30 to control the driver 40 to operate
the stepping motor 38 to set the print wheel 34 to the
selected postage value. Simultaneously, the micro-
computer obtains the information reyarding the selected
postage print wheel setting value from the amplifier
comparator 42 which is coupled to the opto-interruptor 44
which senses the rotation of the print wheel by detecting
the motion of the slott~d disk 46. This provides infor-
mation regarding the actual setting o~ the print wheels
34. The information is evaluated in the microcomputer 30
and if an error is detected between the inten~ed value to
be set into the print wheel 34 and the actual value
detected the microcomputer will prevent the postage
printing drum from being energized to rotate and will
~5 additionally reduce the setting speed for the next
setting of the postage printing wheel 34.
Re~erence is now made to FIGURE 3 which shows a
postage meter system similar to F~GURE 2 but having a
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postage setting driver motor 66 located external to the
postage meter secure protective housing 15. The setting
motor is connected to the printwheel 34 by a mechanism 68
which projects through the secure housing 15. The
operation of the system shown in figure 3 is similar to
the operation noted above in connection with FIGURE 2,
however an additional microcomputer 70 (~7ith associated
circuitry not shown) is provided for controlling driver
72 to operate the setting drive motor 66. Microcomputer
70 is coupled to the external communications channel and
then over bus 16 to the electronic postage scale 14. The
microcomputer 70 may be part of the postage meter base 24
for controlling operation of the base.
It should be recognized that the magnitude of the
speed increase or decrease will be determined empirically
for di~ferent mechanisms and drives. Moreover, the
setting speeds for any given mechanism cannot be contin-
ually increased to higher and higher setting speeds as
eventually the motors or drive will fail to respond, will
hang up or will break, either as the speed is increased
or the mechanism is employed to print postage on mail
pieces which require a higher torque. Thus, an upper
limit on the setting speed may be resident in the oper-
ating program in the read only memory 32 to preclude such
~5 problems~
Referen~e is now made to FIGURE 4. FIGURE 4 is a
flow chart o tha~ po~tion oE the postage meter operating
program resident in the read only memory 32 for con-
~.2~
trolling the speed at which the print wheels are set.
In general and as will be described in greaterdetail in connection with the description of the flow
chart, when power is turned on, the microcomputer exe-
cutes an initialization routine. This routine sets aflag to be tested by the stepping motor contro~ling
routine. When the stepping motor controlling routine is
called, it tests the flag, and if the flag has been set,
it increases the motor stepping rate by reducing the time
period between steps before executing the routine. Each
time a new setting activity is initiated, this flag test
routine is repeated and the constant determining the
step time will be reduced by a predetermined percentage
and the setting speed thereby increased. When an error
is detected, the motor controlling microcomputer is
required to enter an error handling routine. This
routine resets the flag previously set by the initializa-
tion routine and reduces the motor speed by lengthening
the step. The motor controlling routine will then find
from this point on, that the flag was reset and will not
modify the setting speed. Thus, the setting speed will
remain constant until either the power is turned of~ and
then turned on causing the flag to be set again or an
error is detected which causes the routine to reduce
the setting speed.
In operation, when power is turned on for the elec-
tronic posta~e meter 14, the meter goes through an
initialization routine and setting speed flags are set
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blo~k 74. The meter may proceed to process other meter
functions block 76. If it is not desired to set the
print wheels decision block 78, the meter may be operated
to process other postage meter functions block 80.
If the postage wheels are to be set decision block
78, an inspection is made to determine whether the print
wheel setting speed flag is set or clear decision block
82. If the print wheel setting speed flag is set the .
program branches to modify the speed controlling constant
to increase the postage setting speed block 84. There-
after, the postage setting motor is driven at a speed
determined by the speed control constant and movement
detected by sensors on the shaft are monitored block 86.
I~ the speed flag is clear, block 86 is entered directly
from decision ~lock 82. If a movement error is not
detected, decision block 88, other postage meter ~unc-
tions may be enabled block 90 and the program accordingly
loops back to block 76 for other postage meter functions.
If, however, a movement error is detected, decision
block 88, the speed flag is cleared block 92 and the
speed controlling constant is then modified to decrease
the postage setting speed block 94. The postage printing
wheels are then re-initialized so that they will be at a
known position block 96. The program thereater loops
25 back to block ~6 wherein the postage meter setting drive
is determined by the speed control constant now entered
into the system.
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Whlle the present invention has been disclosed and
described with reference to the above noted embodiment,
it will be apparent that variations and modifications may
be made therein. It is, thus, intended in the following
claims to cover each variation and modification as falls
within the true spirit and scope of the present invention.
