Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
PROGRAMMED ElECTRONIC KEYCORDER UNIT
FIELD OF THE INVENTION
The present invention relates to control devices
and, more particularly, to a controL device for limiting
access to a machine or other equipment or device to
authorized personnel possessin~g a card unit which furth-
er contains stored data controlling the e~tent of access
to the machine permitted to the holder of the card unit.
BACKGROUND OF THE INVENTION
A number of applications e~ist wherein it is desir-
able to limit access to machines to only those personshaving proper authorization and further to limit the
extent of such access. As one example, it is sometimes
desirable to limit the use of copier machines to select-
ed personnel. The copier machine is often provided with
a substantially tamper proof counter for maintaining a
cumulative count of the number of copies which have been
produced to date. One standard technique for authoriz-
ing use of the copier machine is to provlde selected
personnel with a conventional key arranged to release a
2Q cooperating mechanical lock which, when opened, may be
arranged to provide for the completion of an electrical
circuit to provide power to the machine. Since keys of
this type may be simply, readily and ine~pensively repro-
duced, one standard prior art approach to avoid simple
reproduction of keys is described in ~.S. Patent No.
3,436,j30, issued April 1, 1969 and assigned to the
assignee of the present application, and which discloses
a control unit forming a part of the copier machine and
arranged to releaseably receive a portable plug-in unit
containing an electromechanical counter and an electri-
cal or electronic circuit element or elements which,
when the portable unit is plugged into the control unit,
5~
serve to operate a relay which couples the machine to a
local power source. The control unit is also preferably
provided with an electromechanical counter.
The machine or device whose access is being control-
led generates pulses representative of machine usage. Inthe copier machine example, each pulse preferably repre-
sents the reproduction oE a single copy. Each pulse is
simultaneously applied to the electromagnetic counters
oE the portable, plug-in unit and the control unit.
Ideally, the counter of the control unit should contain
a count equal to the grand total of the individual
counts in each of the portable plug-in units used in
conjunction with that copier machine.
The above mentioned accountability system, although
reasonably satisfactory for cost allocation purposes,
fails to provide any means for limiting the e~tent of
access which any authorized holder of a portable, plug-
in unit.
This limitation led to the development of the sys-
tem described in U.S. Patent No. 3,921,875, issued Novem-
ber 25, 1975 to the assignee of the present application.
The apparatus described in the last mentioned patent
also comprises a control unit forming part of the mach-
ine and a portable, plug-in unit. The portable unit
contains an electromechanical counter which may be pre-
set to any desired count from 0 to a count of up to
99999, for e~ample. The portable unit is also provided
with an electrical circuit for operating a relay to
couple the machine whose usage is being regulated to a
local power source. Pulses generated by the machine and
representative of machine usage are applied to the elec-
tromagnetic counter of the control unit and to the
~2~
electromagnetic counter of the portable unit to respec-
tively increment the control unit counter and decrement
the portable unit counter. When the count in the port-
able unit counter has been decremented to a predetermin-
5 ed value (preferably 0) a switch is opened to deenergizethe aforementioned relay and thereby decouple the mach-
ine from its source of power.
The count itl the electromechanical counter of the
plug-in unit may be reset by opening the plug-in unit
through the use of a mechanical key. Alternatively, the
count may be advanced through the use o a pulsing
device which applies the number of pulses to the electro-
mechanical counter equal to the desired count to be
stored therein. This is a sluggish and tedious operation
due to the electromechanical nature of the counter which
is further subject to wearing over a period of continu-
ous use. The portable plug-in units and control unit are
also unnecessarily large and subject to wearing and
breakdown due to the large number of mechanical moving
parts utilized in these units.
In addition to the above disadvantages, the port-
able unit housing may be broken into rather easily and
the electromagnetic counter mechanism may easily be tam-
pered with to create a non-zero count condition, thereby
destroying system security. The electromechanical nature
of the device also lends itself readily to evaluation of
the contents to further aid unauthorized personnel in
their quest to defeat the security measures and thereby
permit unauthorized use of the machine or device being
protected against unauthorized use.
.1
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BRIEF DESCRIPTION OF THE INVENTION
The present invention avoids all of the disadvantag-
es of prior art systems and is characterized by compris-
ing three basic subassemblies, each utilizing solid
state circuits to totally avoid the disadvantages of
large size and weight and wearing of components normally
encountered in the prior art devices, such as those des-
cribed, for example, in the above mentioned U.S. pat-
ents, and which present invention yields additional ad-
vantageous features as will be more fully described.
The three basic units employed in the solid statesystem of the present invention are a card unit, card
reader unit and card programmer unit. The card unit is
comprised of miniaturized solid state circuitry includ-
ing an up/down counter, a multiplexer and a battery, allof which are arranged within a housing whose overall
dimensions are of the order of a conventional credit
card.
The card programming unit is substantia]ly compris~
ed of all solid state components including a display and
driver circuit. When a card unit is inserted into the
card programmer unit, a control circuit sequentially
transfers the count in the card unit counter through the
card unit multiplexer and the card programmer unit demul-
tiplexer to a driver circuit for displaying the contentsof the card unit counter.
The count desired to be added to the card unit is
set into manually settable switches.
Depression of a program start button in the pres-
ence of a card unit sets the count of the settableswitches into the card programmer unit counter and enab-
les a normally disabled clock in the card programmerunit counter. Pulses from the local oscillator increment
the count of the card unit counter and simultaneously
decrement the count of the card programmer counter.
I.ogical gates, which continuously monitor the card prog-
rammer counter, deactivate the local oscillator and sim-
ultaneously disable a previously enabled gate preventing
spurious oscillator pulses from reaching the card unit
counter. The card programmer display displays the count
in the card unit counter to provide positive confirma-
tion that the correct count has been added to the card
unit, as well as displaying the count in the card unit
prior to and during insertion of the desired count.
A card reader unit, which is interconnected with
the machine whose use and extent of use is to be
controlled, is provided with solid state decoder drivers
for driving a visual display.
A control unit controls the card unit multiplexer
in synchronism with a card reader unit solid state
demultiplexer for sequentially transferring the count in
the card unit counter to the dècoder driver circuit.
The card reader unit further incorporates a local
oscillator which operates the control unit for operating
the multiplexer and demultiplexer circuits in synchron-
ism and provides time division pulses to the visualdisplay.
The display driver circuits convert the data trans-
ferred thereto from the card unit counter into signals
appropriate for illuminating the display device which is
preferably of the seven segment LCD (liquid crystal
display) type. Selected ones of the signals of each
decimal digit position of the display are coupled with
i,
$~5~
logical gating circuitry which operates to energize a
relay for providing a machine enabling signal and for
deenergizing a relay to disable the machine when the
count in the card unit counter is decremented to zero by
pulses derived from the machine, which zero count is
also displayed by the card reader unit display.
Pulses representative of machine usage are applied
to the card unit counter through the card reader unit to
decrement the contents of the card reader unit counter
upon the occurrence of each count pulse.
The simplified, miniaturized, solid state design
eliminates the need for a card reader unit display and
its attendant cost and weight, reducing the card reader
unit, for example to a weight of no greater than one
ounce, as compared with key counter units which, in
addition to being relatively large and bulky, are more
than five times the weight of the card unit.
The solid~state multiplexer and demultiplexer units
si&nificantly reduce the electrical connections required
between the card programmer unit and the card unit and
between the card reader unit and the card unit. The
small battery employed in the card unit is capable of a
significantly long, useful operating life due to the
elimination of a display in the card unit and the
provision of single, visual display means in only the
card reader and card programming units~ yielding a signi-
ficant reduction in cost and which is a direct function
of the number of card units employed within a single
system. As an alternative arrangement, the card unit may
employ a rechargeable battery which is designed to be
recharged either during the time that the card unit is
being programmed to receive a new count or at the time
;
the card unit is inserted into a card reader unit.
The system enhances centralized control or, alterna-
tively, provides a prepayment capability.
The system employs extremely low power solid state
integrated circuits as wel.l as display devices which
consume almost no power since they operate with low
conductivity electro- statics and thereby consume signi-
fi.cantly less power than prior art. devices presentl.y in
use.
The ci.rcuit connections required to be made to the
card reader unit serve as additional security means
since specific knowledge of the machine construction
would be required to have any reasonable chance of
making the required connections.
OBJECTS OF THE INVENTION AND
BRIEF DESCRIPTION OF THE FIGURES
It is therefore one object of the present invention
to provide a novel~ highly sim`p~lified solid state con-
trol system for controlling access to a machine and the
extent of such access by means of a preprogrammed card
~nit having a solid state counter selectively engageable
with a card reader unit for displaying the present count
in the card reader unit, for decrementing the count
responsive to machine usage and for locking the machine
against further usage when the count in the card unit
reaches a predetermined count.
Another object of the present invention is to pro-
vide a control system of the type described in which
solid state programming means is provided for simply,
rapidly and accurately entering a preprogrammed count
into the solid state counter of a card unit and includ-
ing display means for displaying the contents of the
card unit counter to confirm entry of the preprogrammed
count.
s~
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Still another object of the present invention is to
provide a control system of the type described in which
system security is obtained through the provision of a
card identity code which is examined by a key acceptor
unit for validity in order to enable the device being
controlled.
The above, as well as other objects of the present
Lnvention, will become apparent when reading the accom-
panying description and drawing in which:
Fig. 1 is a schematic diagram of a card reader unit
embodying the principals of the present invention.
Fig. la shows a perspective view of the card unit
exterior.
Fig. 2 is a schematic diagram showing the solid
state card programmer employed for introducing a prepro-
grammed count into a card unit of the type shown in Fig.
Fig. 3 is a schematic diagram of a card reader unit
arranged for selective insertion of a card unit of the
type shown in Fig. 1 for controlling the access and
extent of access of a machine coupled thereto.
Fig. 4a shows a front view of the card reader unit.
Fig. 4b shows a sectional view of the card unit of
Fig. 4a and an end view of the card unit of Fig. la.
DETAILED DESCRIPTION OF THE INVENTION
One preferred embodiment of the card unit 10 of the
present invention is shown in Figs. 1 and la, Fig. la
showing the outward physical appearance thereof, wherein
it can be seen that the card unit 10 comprises a thin~
rectangular shaped body 12, preferably formed of plas-
tic, and containing solid state circuits (to be more
~2~
g
fully described) embedded therein. The body 12 generally
resembles a conventional credit card but has a slightly
greater thickness T. One end 12a, of a reduced thickness
portion is provided with an edge connector assembly 13
for insertion into an edge connector socket to be more
fully described, said socket 13 including individual end
terminals 13a.
The card unit 10 comprises a solid state counter 14
oE the binary coded decimal type which, in ~he preferred
embodiment of Fig. 1 is further comprised of four C~IOS
type 4510 integrated circuits or stages 14-1 through
14-4 electrically connected to form an up/down counter
14, each stage capable of storing a decimal number. A
battery 16 powers the counter 14. Battery 16 is shown
schematically but may, for example, be comprised of a
pair of 1.5 volt watch batteries of the type 393BP, and
being connected in series. Diode 18 serves as a blocking
circuit device to prevent charging o~ battery 16 by
external connections.
20Each counter stage 14-1 through 14-4 has its clock
input 14-la through 14-4a``connected in common to a count
input terminal 20. The carry outputs 14-lb through 14-3b
of stages 14-1 through 14-3 are electrically connected
to the carry inputs 14-2c through 14-4c of counter
25stages 14-2 through 14-4.
The binary coded decimal output terminals 14-ld
through 14-lg and 14-4d through 14-4g are selectively
connected to respective inputs 22a through 22h and 24a
through 24h of solid state multiplex circuits 22 and 24
which are preferably type 4052 integrated circuits which
multiplex ~i.e. sequentially transfer) the digital data
stored in counter 14 to the output terminals 22i and 22j
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of circuit 22 and 24i and 24j of circuit 24. The
multiplexed data output terminals being labelled A, B, C
and D respectively. Input lines labelled E and F are
adapted to apply binary type control signals derived
from an external source 30 or 90 to the control termin-
als 22k and 221 of circuit 22 and 24k and 241 of circuit
24 to control the multiple~ing and demultiplexing opera-
tion as will be more ully described.
Control inputs 14-lh through 14-4h of the counter
stages comprising counter 14 are connected in common to
a terminal 26 arranged to be electrically connected with
either the card reader unit or the card programmer unit
and to receive a binary level signal from the card
reader unit causing the counter to be decremented when
count pulses are applied to terminal 20 and alternative-
ly arranged to receive an opposite level binary signal
causing counter 14 to be incremented when count pulses
are applied to input 20 by the card programming unit 30,
which operations will be more fully described hereinbe-
low.
The embodiment of thè card unit 10 shown in Fig. 1
is thus capable of storing any count from 0000 through
9999. Obviously, the count capacity may be increased by
adding one or more additional counter stages, if desired.
The card programmer unit 30, as shown in Fig. 2,
functions to generate an exact number of pulses equal to
the count desired to be added to a card unit 10 inserted
into the card programmer unit 30.
This is accomplished by means of thumbwheel switch-
es 32 through 38 each having their binary coded outputs
electrically connected to associated inputs of a counter
40 (comprised of solid state counter stages 40-1 through
3~2(~5~
40-4) which are preferably type 4510 counter stages
arranged to operate as a decrementing counter.
A local power supply 42 provided in card programmer
unit 30 converts a 115 VAC source through transformer Tl
and full-wave bridge 44 to a DC signal. A type 7805
Cil^CUit 46 provides a stabilized +5 VDC output which is
coupled through terminal 48 forming part oE a card
programmer unit receptacle to terminal 50 forming part
of the edge connector 12a of card unit 10 (shown in Fig.
1). Termina] 52 of card unit 10 is, in turn, coupled to
terminal 54 of card programmer unit 30, shown in Fig. 2.
Thus, when a card unit 10 is inserted into the connector
forming part of the card programmer unit 30, an electri-
cal circuit is completed from the ~5V terminal 48 to
terminal 50 of the card unit 10 and back to the card
programmer unit 30 through lead 51 and terminal 54,
which voltage is applied to the set input 56a of bista-
ble flip-flop 56, causing its Q ouput 56b to go high.
This voltage appears at terminal 58a of programming
switch 58 and, when switch button 58b is pressed, comple-
tes an electrical circuit to stationary terminal 58c to
apply a high signal to the set input 60a of bistable
flip-flop 60 causing its Q output 60b to go high and
causing its Q output 60c to go low.
The Q output of bistable flip-flop 60 is simultan-
eously applied to each preset input 40-la through 40-4a
of the counter stages of counter 40 causing the binary
values, established by the settings of thumbwheel switch-
es 32-38, to be preset into a respective one of the
counter stages 40-1 through 40-4. Thumbwheel switches 32
through 38 are of a conventional type in which, by opera-
tion of a control knob such as control knob 32e, any
number from decimal "zero" through decimal "nine" may be
set within window 32f thereby providing a four bit
binary output which is coupled to the input of the
associated counter stage.
S The Q output of bistable flip-flop 60 is further
simultaneously applied to the reset terminal 62a of a
type 555 timer which, by appropriate selection of the
resistance va]ues of resistors Rl and R2, and the capaci-
tance values of capacitors C1 and C2, is operated as an
oscillator which, in the present application, generates
pulses at a rate of the order of 2kHz at its output
terminal 62b. The output of oscillator 62 is coupled to
input 64a of NAND gate 64 whose input 64b is also
coupled to the Q output 60b of bistable flip-flop 60.
The Q output of flip-flop 60 removes the reset level
from inputs 40-lc through 40-4c of counter 40 enabling
counter 40 to be preset.
The Q output of bistable flip-flop 60 also enables
NAND gate 64 to pass clock pulses from clock source 62.
These pulses are simultaneously gated through NAND gates
66 and 68 which are wired to operate as inverters.
Output 66a of NAND gate 66 is coupled in common to the
clock inputs 40-lb through 40-4b of the counter `stages
of counter 40, which counter is operated as a decrement-
ing counter whose count is reduced from the settingpreset into the counter 40 by thumbwheel switches 32
through 38, toward a zero count.
Output 68a of NAND gate 68 is coupled through
terminal 70 of card programmer unit 30 to terminal 20 of
card unit 10 shown in Fig. 1 causing the count in
counter 14 to be incremented simultaneously with the
J
~5~.~
decrementing of the count in counter 40.
Assuming that the counter 40 of card programmer
unit 30 has been preset to introduce a decimal count of
1000 into the card unit counter 14, after clock source
62 has applied 1000 pulses to card unit counter 14 and
to card programmer unit counter 40~ all four counter
stages 40-1 through 40-4 will have been decremented to
zero. A pair of eight-input NOR gates 74 and 76 have
respective ones of their inputs electrically connected
i0 to respective ones of the binary coded outputs of count-
er stages 40-1 through 40-4. Gate 74 has its eight
inputs respectively coupled to four outputs of stage
40-4 and stage 40-3, while gate 76 has its eight inputs
respectively coupled to the four binary coded outputs of
stages 40-2 and 40-1, respectively.
Diodes Dl and D2 electrically connect the outputs
of gates 74 and 76 to common terminal 78 arranged
between resistor R3 and capacitor C3.
When all si~teen outputs of counter stages 40-1
through 40-4 are low~ representing the decimal number
0000, the outputs of both gates 74 and 76 go high
raising common terminals 78 to the +5V level, which
level is simultaneously applied through conductor 80 to
reset inputs 56c and 60d of bistable flip-flops 56 and
60, respectively. The Q output of bistable flip-flop 60
simultaneously disables gate 60 and terminates the opera-
tion of clock source 62 preventing any noise from inad-
vertently pulsing the card unit counter 14 and thereby
adding a false count to the card unit. The Q output of
flip-flop 60 goes high preventing counter 40 from being
accidentally preset. The resetting of bistable flip-flop
56 causes its Q output to go low preventing the program-
- 14 _
ming operation from being repeated in the event that
program button 58 is accidentally operated before the
card unit 10 which has just had a preprogrammed count
added to it, has been removed from the card unit recep-
tacle forming part of card programmer unit 30.
The card programmer unit 30 ls further provided
with a solid state demultiplexer and control circuit 82,
a display driver ci.rcuit 84 and a four di.git displ.ay 86
which are substantially identical to Like circuits provi-
ded within card reader unit: 90 (to be more f~llly describ-
ed hereinbelow). The inputs 82a through 82d of demultipl-
exer 82 receive the A through D outputs of multiplexers
22 and 24 provided in card unit 10. The demultiplexer
and control circuitry 82 transfers the binary coded
count stored in the stages of card unit counter 14
through multiplexer circuits 22 and 24 and demultiplexer
82 to the display driver circuitry 84 for illuminating
display 86, which is preferably provided with four deci-
mal display units, each being of the seven segment
decimal type. A detailed description of the transfer of
data from the card unit counter 14 to the card reader
unit visual display 86 will be set forth in detail
hereinbelow, it being understood that the operation of
the same circuitry within the card programmer unit 30 is
substantially identical to that provided in card reader
unit 90.
Card programmer unit 30 thus makes it possible to
enter an exact preprogrammed count into the card unit
counter 14 in a simple, rapid manner, the entire opera-
tion taking, at most, a few seconds including set up,insertion and removal of the card unit 10. The display
86 provided within the card programmer unit 30 provides
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direct visual confirmation that the preprogrammed number
has been correctly introduced into the card unit lØ The
display 86 also serves as a means to ascertain the count
within the card unit 10 before initiating a programming
operation and further enables a preprogrammed count to
be added to a card unit counter 14 which has other than
a æero count when first introduced into the card program-
ming unit 30.
The card reader unit 90, shown ln detail in ~ig. 3,
perEorms the functions of: displaying the four digit
decimal number contained wlthin the memory of the card
unit 10 inserted into the card reader unit receptacle
and enabling the machine being controlled by the card
reader unit 90 when the count in the card unit 10 is
other than zero. However, when the count in the card
unit 10 reaches zero, the card reader unit 90 causes the
machine to be made inoperative.
Card reader unit 90 recovers the count in card
reader unit 10 by demultiplexing the binary coded inform-
ation on the four lines labelled A through D which arerespectively coupled to solid state demultiplexer cir-
cuits 92 and 94 which are preferably type 4052 integrat-
ed circuits. Input terminals 96 and 98, receiving data
bits A and B, are coupled to inputs 92a and 92b of
demultiplexer circuit 92 while terminals 101, 102 couple
data bits C and D to inputs 94a and 94b of demultiplexer
circuit 94.
Control signals for controlling the transfer of the
count from card unit 10 to the card reader unit 90 are
derived from solid state circuit 104 which is preferably
a type 4029 circuit having a clock input 104a coupled to
the output of a lOOHz oscillator 106 for developing
~2~)~5~
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binary coded decimal control signals E and F at the
outputs 104b and 104c, respectively.
The E and F signals are applied: through terminals
108 and 110 to the control inputs 22k, 221 and 24k, 24~
of multiplexer circuits 22 and 24 in card unit 10 (shown
in Fig. l); and are simultaneously applied to the con-
trol inputs 92c, 92d and 94c, 94d of demultiplexer
circuits 92 and 94; and to the inputs 112a and 112b of a
binary coded decimal to decimal decoder circuit 112
; 10 which is preferably a type 4028 solid state circuit
arranged to convert a two bit binary coded input into a
radix four ("one of four") output.
Each of the multiplexers 22 and 24 of card unit 10
has four pairs of input terminals for a total of eight
input terminals 22a through 22h and 24a through 24h. The
binary coded multiplexer control signals E and F are
simultaneously applied to the aforementioned control in-
puts of multiplexers 22 and 24 to cause only one pair of
the four pair of input signals to appear at output
terminals 22i, 22j and 24i, 24j of the multiplexer units
22 and 24, in accordance with the binary code applied to
the control inputs 22k, 22~ and 24k, 24~. For example,
when control signals EF develop a binary code OjO, the
binary levels at outputs 22i and 22j are respectively
coupled to inputs 22a and 22b, while the binary levels
at outputs 24i and 24j are respectively coupled to
inputs 24a and 24b causing the four binary bits represen-
ting the least significant decimal position, stored in
counter stage 14-1, to appear at data output terminals A
through D respectively.
Simultaneously therewith, control signals E and F
control the demultiplexer circuits 92 and 94 so that the
~o~s~
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input signals appearing at 92a, 92b are transferred to
ouputs 92e and 92f and so that the inputs 94a and 94b
are transferred to outputs 94e and 94f. These output
pairs 92e-92f and 94e-94f are respectively coupled to
inputs 116a through 116d of latched decoder driver cir-
cuit 116 forming part of the driver array 114 which
further includes latched decoder driver circuits 118,
120 and 122. Solid state circuits 116 through 122 are
preferably type 4056 circuits capable of converting a
binary coded decimal input into a group of signals which
selectively appear on output lines 116f through 1161 for
driving a seven-segment decimal display unit such as,
for example, unit 124 coupled to the aforementioned
seven output lines of the driver circuit, such as for
example driver circuit 122, in order to selectively
illuminate two or more of the display segments 124a
through 124g which collectively cooperate to form the
decimal digits "0" through "9".
The four binary signals representing the least sig-
nificant decimal digits are loaded into driver circuit
116 by decoder 112 which decodes the two bit binary
control signals E, F applied to inputs 112a, 112b to
cause one of its four output lines 112c through 112f to
develop a strobe signal, to the exclusion of the remain-
ing three output lines. In the present instance, decod-
er 112 decodes the control signals E and F causing its
output line 112 to develop a strobe pulse for latching
the four binary bits representing the least significant
decimal digit into latched decoder driver circuit 116.
Circuit 116 decodes the four binary inputs and develops
signal levels at the outputs 116f through 116~ represent-
ative of the decimal digit to be displayed, which sig-
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nals are applied to the display unit, such as unit 124
to display the appropriate decimal digit.
The outputs of control signal generating circuit
104 change at a rate controlled by oscillator 106 caus-
ing the next significant decimal digit to be transferredthrough multiplexer circuits 22 and 24 of card unit 10
to the demultiplexer circuits 92 and 94 of card reader
unit 90 thereby causing the binary coded signals repre-
senting the next significant decimal digit to appear at
outputs 92g and 92h of demultiplexer 92 and 94g and 94h
of demultiplexer 94, which signals are applied to respec-
tive inputs 118 through 118d of driver circuit 118. The
control signals E and F are also applied to decoder 112
causing a strobe signal to be developed at output 112d
to transfer and latch the next significant decimal digit
into driver circuit 118 for display by its associated
display unit (not shown for purposes of simplicity).
This operation is continued until all four decimal dig-
its are transferred to the associated driver circuits
116 through 122 and displayed by their associated dis-
play units, which are preferably of the liquid crystal
display (LC~) type. The data transfer operation is also
continuously repeated at the lOOHz rate.
Clock pulses from source 106 are further simultan-
eously applied to the control inputs 116m through 122mof driver circuits 116 through 122 and to the input 124a
of the display unit 124 for generating the liquid crys-
tal display square wave signal which causes the display
unit 24 to operate in an intermittent ~ashion as is
conventional with such units, the pulsing of the display
units in array 130 by clock source 106 being at a rate
sufficiently rapid to cause the eye of the observer to
perceive a "steadily illuminated" decimal digit. The
remaining display units function in an identical fashion.
~, .
53 ~L
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The transfer of the count in card reader unit 10 to
the driver circuit array 114 is continuously updated
since the count in the card reader unit 10 is being
decremented at a rate determined by machine usage. Assum-
ing that the machine controlled by card reader unit 90is a copier machine, the copier machine is enabled in
the folLowing fashion:
The card unit 10 is inserted into the receptacle of
the card reader unit 90 which automatically initiates
transfer of the count in card unit 10 to the driver
circuit array 114. In addition to the count being dis-
played by the display array 130, logical gating circui-
try 132 continuously monitors the driver array 114 to
detect for the presence of a zero count condition. A
unique condition exists for digit zero since the segment
of the display whose illumination is controlled by out-
put 116k will have a voltage on it and the segment whose
illumination is controlled by output 1161 will have no
voltage on it. Outputs 116k, 118k, 120k and 122k are
directly connected to diodes D2, D4, D6 and D8 whereas
outputs 116~, 118~, 120~ and 122~ are connected to
diodes D3, D5, D7 and D9 by inverter circuits Il through
I4 respectively. Thus, when all digits displayed are
decimal zero, a forward base drive is applied to the
base electrode of transistor TRl causing its collector
to go to ground and removing base drive from the base
electrode of transistor TR2 thereby deenergizing relay
Sl. Relay contact Sla is then opened thereby developing
an open electrical circuit between terminals 134 and 136
which may, for e~ample, be utilized to decouple the
machine from its local power source or to provide any
other desired disabling function sufficient to prevent
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further use of the machine when the count in the card
unit inserted into the card reader unit has been decre-
mented to zero. The fact that the card reader unit
contains a zero count is confirmed by the display array
130.
The copier machine, as is conventional, develops
pulses which are applied to pulse inputs 13~ and 140
coupled through a full-wave diode bridge 142 to a signal
stabili~ing circuit 144 comprisecl o resistors R6 thr-
ough R8, zeneor diode ZDl and capacitors C4 and C5, theoutput of the signal stabilizing circuit being coupled
to count pulse output terminal 146 through inverter IS.
Terminal 146 is coupled to terminal 20 of card reader
unit 10 when the card unit 10 is inserted into the
receptacle of the card reader unit 90. Terminal 150
applies a ground level to the terminal 26 of card unit
causing counter 14 to operate as a down counter
whereby pulses representative of machine use applied to
card unit 10 to cause the count in counter 14 to be
decremented.
Although the applicatio~ set forth hereinabove des-
cribes the system of the present invention for use with
a copier machine, it should be understood that the
system is readily adaptable for use with other machines
and/or devices. For e~ample, the system of the present
invention may be utilized for dispensing items and mater-
ials such as, for e~ample, fuel oil, wherein a fuel tank
dispenser is enabled and signals are developed represent-
ative of the amount of fluid dispensed to reduce the
count in the card unit counter 14. The dispenser may
also be a vending machine of the automatic type, wherein
the vending machine is provided with processing means
s~
- 21 -
for comparing the cost of the selection with the present
contents of the card unit wherein the item is dispensed
only when the counter contents equals or exceeds the
cost of the selected unit. The system may also be
employed with point of sale equipment wherein the
operator at a register enters the cost of the item
selected for purchase and the register is enabled only
if the count in the card unit is at least equal to the
cost of the selected item, in which case the register
creates a record and receipt of the sale and substantial-
ly simultaneously therewith reduces the count in the
counter unit by an amount equal to the magnitude of the
sale. An automatic vending machine may also be operated
to vend an item upon receipt of a card unit containing a
sufficient count.
For purposes of the present invention, it is suffic-
ient to understand that the control unit serves as the
interface for coupling the count in the card unit 10 to
display means and possibly to other means for determin-
ing the presence of a valid card unit, for example, andfor providing an enabling signal when the card reader
unit 90 receives a card unit 10 of the proper electrical
configuration and containing a non-zero count,` these
capabilities being designed in a sufficiently universal
fashion for use with a wide variety of different machin-
es and/or devices.
The internal wiring arrangement of the card unit 10
relative to its edge connector may be designed so that
precise knowledge of the circuit contents of the card
unit would be required in order to enable either a card
programming unit 30 or a card reader unit 90 thereby
providing still further security for the system, in
addition to controlling the access to the machine and
the extent of said access as a function of the count
within the card unit.
The front of acceptor unit 250 is shown in Fig. 4a
while Fig. 4b shows a sectional view of its internal
physical arrangement. The acceptor unit 250 is provided
with an opening 272 for receiving the key unit 2Q0 whose
physical arrangement is shown in Fig. la. The rear end
of opening 272 is provided with receptacle means 274 in
the form of a multi-terminal electrical socket assembly
having individual terminals 274a arranged to elec-
trically engage respective ones of the terminals 13a
integrally formed within the edge connector assembly 13
of key unit 10.
When key unit 10 is inserted into slot 272 so that
its edge connector assemb]y 13 is properly inserted
within multi-terminal socket 274, an electrical circuit
is established from the acceptor unit terminals 150
(Fig. 3) to a key unit terminal 51 (Fig. 1) for acti-
vating the key unit 10.
In a similar fashion, the outputs of multiplexers
24, 26 of key unit 10 (Fig. 1) each electrically connect
with a respective one of the inputs of demultiplexers
92, 94 connected to the multi-socket 274 arranged at the
rear of key slot 272.
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- 23 -
Although the preferred embodiment described herein
is designed to increment the count in a card unit 10
when a count is to be added and to decrement the count
when the count is to be removed, the reverse arrangement
is also possible. For example, the count in the card
unit counter 90 may be exhausted when the count reaches
the equivalent of decimal 9999, a count of less than
decimal 9999 representing an unexhausted incard unit l0.
In such an example, the card unit 10 would be decrement-
ed from 9999 to a smaller number under control of thecard programming unit and would be incremented from the
lower decimal number toward the decimal count 9999, at
which time the machine being controlled would then be
turned off. By rearranging the wiring of the driver
circuits of array 114 the signals may be decoded so that
a decimal count of 9999 would be displayed as a decimal
count of 0000 thereby adding still further security to
the system and rendering a defeat of the system more
difficult to unauthorized users who also lack knowledge
of the system design.
A latitude of modification, change and substitution
is intended in the foregoing disclosure, and in some
instances, some features of the invention will be employ-
ed without a corresponding use of other features.
Accordingly, it is appropriate that the appended claims
be construed broadly and in a manner consistent with the
spirit and scope of the invention herein.
