U.S. patent number 3,641,498 [Application Number 05/023,272] was granted by the patent office on 1972-02-08 for keys for electronic security apparatus.
This patent grant is currently assigned to R. B. Phinizy. Invention is credited to Robert A. Hedin.
United States Patent |
3,641,498 |
Hedin |
February 8, 1972 |
KEYS FOR ELECTRONIC SECURITY APPARATUS
Abstract
A key is constructed with a base member of epoxy glass on which
are electrically conductive contact strips offering a binary code
permutation of open and closed circuit paths for controlling a
security apparatus such as an electronic lock or computer. The code
permutation can be established in the key by applying electric
current that changes the state of the circuits on the key. For the
purpose, the key circuits are equipped with fusible elements or
magnetic memory elements. The memory elements may be of a type that
will change the code when the key is used. The key may have a
portion forming an identification card. In further forms the key
will have eddy current rings that will react when applied to proper
key-receiving means, and the key may comprise an optical mask
containing a binary code in the form of a pattern of opaque and
translucent areas.
Inventors: |
Hedin; Robert A. (San Pedro,
CA) |
Assignee: |
Phinizy; R. B. (Anaheim,
CA)
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Family
ID: |
21814111 |
Appl.
No.: |
05/023,272 |
Filed: |
March 27, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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628599 |
Apr 5, 1967 |
3544769 |
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889666 |
Dec 31, 1969 |
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Current U.S.
Class: |
235/487;
235/382 |
Current CPC
Class: |
G07C
9/00944 (20130101); G07C 9/29 (20200101) |
Current International
Class: |
G07C
9/00 (20060101); H04q 009/00 () |
Field of
Search: |
;340/149,166,173,164,147
;235/61.11A |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Optical Hole Sensing Using Fiber Optics" Stahl et al., Applied
Optics July 1966, Vol. 5, No. 7, p. 1203-1206. .
"Memory Array" Dewitt et al., IBM Technical Disclosure Bulletin
Vol. 10, No. 1, June 1967, p. 95..
|
Primary Examiner: Yusko; Donald J.
Parent Case Text
This application is a continuation-in-part of the earlier U.S. Pat.
applications of Hedin Ser. No. 628,599 filed Apr. 5. 1967, now U.S.
Pat. No. 3,544,769 entitled Electronic Identification and Credit
Card System, and of Hedin et al. Ser. No. 889,666 filed Dec. 31,
1969, entitled Key Controlled Electronic Security System.
Claims
I claim:
1. A key for effecting operation of an electronic security
apparatus by the application of a binary coded activating signal
thereto, said key being adapted to contain a binary code
permutation of circuits, said key comprising a plurality of
electrically conductive members for engaging contacts of a key
receiving means through which the permutation code may be applied
to the electronic security apparatus, electrically changeable
binary state memory means connected between said conductive members
so as to be effective when activated to establish a binary coded
permutation on the key, said memory means having first and second
states for establishing said binary coded permutation of circuits,
said memory means when in said first state establishing one binary
coded permutation of circuits and when in said second state
establishing another binary coded permutation of circuits, said
memory means being changeable between said first and second states
to establish the one and the other binary coded permutation of
circuits, said key-receiving means being operably connected to a
source of power for directing power from said contacts to at least
one of said conductive members to energize said binary coded
permutation of circuits and establish said binary coded permutation
of circuits which is indicative of the state of said memory means,
said binary coded permutation of circuits being operable when said
memory means is in a predetermined one of said states to activate
the electronic security apparatus, said binary coded permutation of
circuits being ineffective to activate the electronic security
apparatus when the memory means is in a state other than said
predetermined one of said state.
2. A key as set forth in claim 1 including circuit means associated
with said memory means on the key for the application of electric
signals changing the state of said memory means.
3. A key as set forth in claim 2, in which said key comprises an
electrically nonconductive forward portion on which said
electrically conductive members are mounted in position for
engaging contacts of the key-receiving means, and a portion
concealing said memory means on a rearward portion of the key.
4. A key as set forth in claim 2 in which said memory means
comprise electronic components forming rows and columns of an
integrated matrix, said columns of said matrix being connected to
corresponding ones of said electrically conductive members, and
further conductive members forming parts of said circuit means for
placing each row of said matrix in circuit with a contact of the
key receiving means.
5. A key as set forth in claim 2, in which there is a further
electrically conductive member for engaging a contact of the
key-receiving means, said further member forming a part of said
circuit means for the application of signals to said memory
means.
6. A key as set forth in claim 5 in which said memory means
comprise a magnetic memory element.
7. A key as set forth in claim 6, in which said magnetic memory
element operatively associated with said circuit means and said
first-mentioned conductive members.
8. A key as set forth in claim 5 in which said memory means
comprise one of said first-mentioned conductive members having a
portion of relatively high-electrical resistance connected to said
further conductive member whereby to be destroyed when a relatively
large electric current is applied through said one conductive
member and said further member.
9. A key as set forth in claim 8, in which said portion of said one
conductive member is a diode.
10. A key as defined in claim 2 wherein said memory means comprises
a magnetic core having two stable magnetic states and said circuit
means for changing the state of said magnetic core includes means
for establishing a magnetic field about said magnetic core to set
said magnetic core in a desired one of said stable magnetic states
and further including second circuit means for reading the state of
said magnetic core including means for establishing a magnetic
field which causes said magnetic core to be in a predetermined one
of said states, said magnetic core remaining in said one state if
said magnetic core is in said one state prior to the application of
said magnetic field by said second circuit means and said magnetic
core changing to said one state if said magnetic core is in the
other state prior to the application of said magnetic field by said
second circuit means.
11. A key as defined in claim 10 wherein the application of said
magnetic field by said second circuit means effects a destructive
readout of the state of said magnetic core and sets said core to
said one state regardless of the state said core was previously
in.
12. A key as defined in claim 11 further including means for
resetting said magnetic core to the state said magnetic core was in
prior to the application of said magnetic field by said second
circuit means.
13. A key adapted to contain binary code permutations of circuits
to be connected to contacts of key receiving means for applying a
predetermined code permutation to an electronic security apparatus
to effect operation thereof comprises, an electrically
nonconductive base member for the key, a plurality of electrically
conductive members mounted in spaced relation to one another on
said base member and having each a surface in position for engaging
a contact of said key-receiving means, a plurality of electrically
changeable memory elements having open circuit and closed circuit
states and connected each between at least two of said electrically
conductive members on the base member of the key, and circuit means
associated with each memory element on the key for the application
of electrical signals changing the state of that element between
said open and closed circuit states so as to establish a binary
code permutation of circuits on the key, said circuit means being
operable to effect the establishment of said predetermined and
other code permutation on said key, said key when having said other
code permutation of circuits being ineffective to actuate said
electronic security apparatus, said key when having said
predetermined code permutation of circuits being effective to
actuate said electronic security apparatus.
14. A key as set forth in claim 13 in which said base member of the
key is substantially flat, each of said electrically conductive
members forming a strip extending longitudinally in position on a
forward portion of the base member for engaging a contact of the
key-receiving means, and a conductive strip extending transversely
on a rearward portion of said base member and comprising a
connection between each memory element and at least two of the
longitudinal strips.
15. A key as set forth in claim 13, in which each memory element
comprises a circuit connected at one end to one of said
electrically conductive members and at its opposed end in common
with a corresponding circuit end of each other memory element.
16. A key as set forth in claim 15, in which said electrically
nonconductive base member is epoxyglass and said memory elements
comprise a relatively narrow fusible portion of one of said
conductive members.
17. A key as set forth in claim 15, in which the key has a further
electrically conductive member for placing the commonly connected
circuit ends of said memory elements in circuit with a contact of
the key-receiving means.
18. A key as set forth in claim 13 in which said memory means
comprise each a magnetic memory element, said memory element being
operatively associated with said circuit means for changing the
state of the element, and said circuit means comprising a conductor
that is adapted to engage a contact of the key-receiving means.
19. A key adapted to contain a binary code permutation of circuits
to be connected with contacts of key-receiving means for applying
the code permutation to an electronic security apparatus, said
electronic security apparatus being actuatable in response to a
predetermined code permutation being applied thereto and being
nonactuatable upon the application of a code permutation other than
said predetermined code permutation thereto, a substantially flat,
electrically nonconductive base member, a plurality of electrically
conductive strips mounted in spaced relation to one another on said
base member, each of said strips extending longitudinally on a
forward portion of said member and presenting a surface for
engaging a contact of said key-receiving means, a conductive common
strip extending transversely on a rearward portion of said base
member, changeable means placing each longitudinally extending
strip individually in closed circuit or alternately in open circuit
relation to said common transverse strip, and means for changing
said changeable means on said key so that the key may be
selectively equipped with said predetermined binary code
permutations of closed and open circuits for actuating said
electronic security apparatus or with said other binary code
permutations so as to prevent the actuation of said electronic
security apparatus in response to engagement of said plurality of
electrically conductive strips with said contacts of said
key-receiving means.
20. A key as set forth in claim 19 in which there are longitudinal
strips and a common transverse strip on each opposed face of the
base member so that the key may offer differing code permutations
when applied in inverted positions to the key-receiving means.
21. A key as set forth in claim 19 in which the key comprises a
member enclosing said changeable means on said rearward portion of
said base member, and said enclosing member having flap portion
that is movable relatively to a position covering said electrically
conductive strips on the forward portion of the base member.
22. A key as set forth in claim 19 in which said changeable means
comprise a plurality of memory elements electrically changeable
between open circuit and closed circuit states, said key further
including a conductive segmental strip extending transversely on a
rearward portion of said base member, each of said memory elements
having a circuit connected between a corresponding longitudinally
extending strip and said common transverse strip and further having
a circuit connected between segments of said segmental strip, and
strip portions for placing said common and segmental strips in
circuit with contacts of the key-receiving means, enabling signals
supplied through the key-receiving means to change the state of
said memory elements whereby to establish said predetermined binary
code permutation that the key can reapply to the key-receiving
means to effect actuation of said electronic security
apparatus.
23. A key for conveying a predetermined code to effect operation of
a controlled device, said key having a plurality of electrically
conductive members for engaging respective contacts of
key-receiving means for conveying said predetermined code thereto
to effect operation of the controlled device, a conductor in closed
circuit relation to a portion of said conductive members and in
open circuit relation to a further portion of said members whereby
to offer a binary code permutation of circuits to said key
receiving means, and a capacitor connected between said conductor
and one of said conductive members, said capacitor providing a
closed circuit path between said conductor and said one conductive
member whereby AC current is applied therebetween to effect the
application of said predetermined code to said key receiving means
and providing an open circuit path to offer a code indication other
than said predetermined code when DC current is applied through the
conductive members.
24. A key for controlling an electronic security apparatus that is
responsive to a predetermined binary code permutation, said key
comprising an electrically nonconductive base member, a plurality
of electrically conductive elements mounted in relative positions
forming a binary code pattern on said base member which is
indicative of said predetermined binary code permutation for
controlling the security apparatus, each of said elements being
shaped to form a closed electrical circuit, permitting the binary
code pattern to be detected through the use of eddy currents that
may be induced in each element upon the application of a changing
magnetic field to said elements, said eddy currents producing a
counter magnetic field which acts to oppose the changing magnetic
field applied to said elements and enables the binary code pattern
to be detected by sensing the magnitude of the applied magnetic
field.
25. In a key for applying a predetermined binary coded permutation
of electrical signals to an electric security system to effect
actuation of the system and having a plurality of contacts through
which the signals are transmitted to the system, circuit means
connected to certain contacts of said plurality of contacts on the
key for establishing a relationship between said certain contacts
that is effective to transmit the predetermined binary coded
permutation of electric signals to effect actuation of the system,
electrically changeable state control means forming a part of said
circuit means for controlling the coded relationship established
between said certain contacts by the circuit means, said control
means having a first state for enabling the key to apply said
predetermined binary coded permutation of electric signals to
effect actuation of the electric security system and a second state
which prevents said key from applying said predetermined binary
coded permutation of electric signals, said control means when in
said second state rendering said key inoperative to actuate said
electric security system and circuit portions through which a
potential will act when externally applied to a certain combination
of said contacts to change the state of said control means to said
first state to enable said plurality of contacts to apply said
predetermined coded permutation of signals to said electric
security system to effect actuation thereof.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to keys that are utilized with
electronic locks and other electronic security apparatus and more
particularly to keys having a binary permutation code stored in a
form which may be accessed electrically, magnetically or
optically.
2. Description of the Prior Art
Recent years have seen increasing acceptance of electronic systems
for controlling entrances to protected areas and for identifying
individuals without the requirement for a guard. Typically, a door
may be provided with an electronic lock which responds to a
preselected binary permutation code contained on a key. A person
wishing to gain entrance through the door inserts his key in a
receptacle associated with the lock, and lock circuitry determines
if the key has the correct coding. If so, an actuation signal is
provided to an electric door latch or strike; if the key has an
improper code, there will be no actuation signal, and at the same
time the system may generate an alarm signal.
Electronic locks have several significant advantages as compared
with conventional lock systems. For example, a very large number of
codes are available on a key of small size. The number of
combinations available may be expressed as follows:
Total number of combinations =(n! /r! (n- r) !) where n is the
number of available binary coded elements on the key, and r is the
number of stored binary one bits required to energize the
electronic lock. For example, for a key having 20 binary coded
elements (n= 20) used with an electronic lock requiring r= 10
stored binary one bits for energization, a total of (20! /10!
10!)=184,756 combinations are available.
In electronic locks, very simple circuit changes permit the lock
rapidly to be changed so as to be actuated by any of the
potentially available key codes. The large number of key
combinations, together with the ease with which alarm means may be
incorporated in the lock, make electronic locks significantly
harder to pick than mechanical systems. Moreover, a large number of
remote electronic key identification stations can be monitored at a
single central control station.
An electronic lock using a binary permutation coded key is
described in U.S. Pat. No. 3,392,558 to R. A. Hedin et al. The
circuitry employed will recognize a particular binary permutation
code stored on a key and will apply a signal to actuate a door
latch or other utilization device. Other electronic lock circuitry
and central electronic security systems incorporating such
circuitry are set forth in the copending application Ser. No.
889,666, mentioned above.
The use of binary coded keys is not limited to the control of
access to protected areas; many other things can be controlled and
a potentially more widespread application is in the field of
automatic crediting. Thus, a credit card may incorporate a coded
key structure identifying the credit customer and containing a
coded indication of the amount of credit currently available to the
individual. Thus, in conjunction with a terminal device located in
a merchant's store and a network of computer facilities, transfer
of funds may be affected automatically between consumer and
merchant. These and other related uses are described in the article
by Robert A. Hedin entitled "Electronic Identification of the Human
Population for Controlled Access and Automatic Crediting",
appearing in the periodical Industrial Security, Vol. 11, No.
2.
Described herein are a variety of keys for use in electronic locks,
automatic crediting systems and the like. While referring merely to
"keys", it is to be understood that the keys may be formed with a
portion that will bear information such as is needed on a credit or
other identification card. The keys disclosed include both
permanently coded and alterable data configurations. The latter
keys are particularly well suited for application wherein data is
to be periodically updated.
SUMMARY OF THE INVENTION
In accordance with the present invention, there are set forth
various keys for use with electronic locks that respond to a binary
permutation code stored in the key. I mention locks for convenience
of description, and when referring to a lock I intend to include
other electronic security apparatus that will be controlled by a
key. In different embodiments, the code may be entered in the key
at the time of manufacture, entered subsequent to manufacture and
thereafter permanently retained, or entered and/or revised at any
time. Depending upon the embodiment, the codes may be sensed
electrically, magnetically or optically.
In one form, the key code may comprise a permutation of open or
closed AC or DC electrical paths in a circuit printed or etched on
an electrically insulative substrate or base member. Keys of this
type may be precoded at the time of manufacture. However, as a
feature of my invention I may equip the keys with elements for
subsequent entry of a binary code permutation.
More particularly, the keys may have memory elements for storage of
the code. These memory elements may comprise single- or
multiple-apertured magnetic cores or other magnetic storage
elements, or may comprise a diode or transistor matrix. Certain of
the magnetic memory element keys are particularly well adapted for
the storage of data which is to be altered from time to time.
Another key embodiment incorporates a plurality of electrically
conductive strips of ring shape located at selected positions on an
electrically insulative, nonmagnetic base member substrate. The
location of these eddy current rings, the presence of which may be
sensed magnetically, represent the code of the key. In yet another
embodiment, the key may include an optical mask containing a
pattern of transparent and opaque areas that form the coding of the
key. The position of the optically coded regions may be sensed
using a fiber optic bundle and an associated plurality of
photodetectors.
Thus, it is an object of the present invention to provide improved
keys for use with an electronic lock or other electronic device
that will respond to a binary code permutation of electrical
circuits.
It is another object of the present invention to provide keys for
electronic locks, which keys contain binary codes which may be
sensed electrically, magnetically or optically.
Another object of the present invention is to provide various
embodiments of keys for electronic locks, wherein a code may be
represented on a key by open or closed electrical paths in a
printed circuit, by data stored in magnetic or other memory
elements, by positions of active components in a diode or
transistor matrix, by the location of eddy current rings on a
nonmagnetic substrate, or by the juxtaposition of opaque and
transparent regions in an optical mask.
Still another object of the present invention is to provide keys
having planar, electrically insulative base members or substrates,
a set of spaced, parallel conductive strip terminals adjacent a
common edge of the substrate and means for electrically connecting
or disconnecting selected terminals to a common conductor also
disposed on the substrate.
It is still another object of the present invention to provide keys
incorporating an electrically insulative substrate or base member
having a plurality of conductive members offering contact-engaging
surfaces thereon, and including memory elements associated with
selected members for storing a binary permutation code.
A further object of the present invention is to provide a coded
device useful as an identification or credit card for use with
electronic code recognition circuitry, the device containing memory
elements permitting storage of alterable coded data.
It is a further object of the present invention to provide a key
wherein the coding is represented by the positions of a plurality
of eddy current rings on a nonmagnetic substrate.
Yet a further object of the preset invention is to provide a key
including an optical mask having juxtaposed opaque and transparent
regions, the coding represented thereby being determinable by use
of a fiber optic bundle in conjunction with a plurality of
photodetectors.
BRIEF DESCRIPTION OF THE DRAWINGS
Still other objects, features and attendant advantages of the
present invention will become apparent to those skilled in the art
from a description of the preferred embodiments constructed in
accordance herewith, taken in conjunction with the accompanying
drawings, wherein like numerals designate like parts in the several
figures, and wherein:
FIG. 1 is a plan view of a printed circuit key having fusible
elements for the entry of a code;
FIGS. 2a and 2b respectively show the top and bottom view of
another key embodiment having a pattern of open and closed
electrical paths in a printed circuit;
FIGS. 3a and 3b illustrate one manner in which a key of the type
shown in FIG. 1 may be constructed to obscure the coding
thereof;
FIG. 4 shows a key constructed according to the invention and
including an identification or credit card portion;
FIG. 5 is a simplified perspective view of a key embodiment wherein
a binary code is represented by a permutation of open or closed AC
electrical paths;
FIGS. 6a and 6b respectively show perspective and cross-sectional
views of an encapsulated key for an electronic lock;
FIG. 7 is a perspective view of a key incorporating a plurality of
memory elements which store coded data;
FIG. 8 is a simplified electrical block diagram of utilization
circuitry for a key of the type shown in FIG. 7;
FIGS. 9a and 9b show various types of magnetic core devices which
may be employed as memory elements in the key of FIG. 7;
FIG. 10 is a sectional view of a thin film magnetic memory element
that may be utilized in the key of FIG. 7;
FIG. 11 is a perspective view of a key employing plated wire memory
elements;
FIG. 12 is a simplified, somewhat diagrammatic view of a key
employing a diode matrix;
FIG. 13 is a perspective view of a key employing an integrated
diode or transistor matrix and requiring an appropriate access code
for interrogation of the key;
FIG. 14 is an electrical schematic diagram of a transistor matrix
array that may be utilized in the key of FIG. 13;
FIG. 15 is a perspective view of a key incorporating a plurality of
ring-shaped electrically conductive strips, the positions of which
may be detected magnetically;
FIG. 16 is a top plan view of a key incorporating an optical mask
coded with opaque and transparent regions;
FIG. 17 diagrammatically illustrates apparatus for accessing the
code contained in the key of FIG. 16.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and particularly to FIG. 1 thereof,
there is shown a first embodiment of a key having certain features
like those which are set forth in the copending applications
mentioned above, Ser. No. 628,599 and Ser. No. 889,666. As
illustrated in FIG. 1, key 10 comprises a substantially flat and
generally rectangular base member or substrate 11 of electrically
insulative material such as epoxy glass. Disposed on a surface of
substrate 11 is a pattern 12 of electrically conductive strips,
which may be fabricated in accordance with conventional electronic
printed or etched circuit techniques.
Pattern 12 (FIG. 1) includes a substantially L-shaped conductor 13,
which I may call a common conductor, having a first portion 13a
extending transversely on a rearward portion of substrate 11.
Conductor 13 also includes a second portion 13b extending toward
front edge 14 so as to form a terminal offering a surface for
engaging a contact of key-receiving means. Pattern 12 also includes
a plurality of spaced parallel conductive strips 15 extending
longitudinally on the forward portion of substrate 11 toward edge
14. Each of conductive strips 15 is electrically connected to
conductor portion 13a via a respective fuse strip 16 formed as an
integral part of pattern 12. Preferably, the width of each of fuse
strips 16 is significantly less than the width of the associated
conductive strip 15, the latter typically being at least five times
as wide as the associated fuse strip 16.
A binary code permutation of open and closed electrical paths may
be provided in pattern 12 by blowing out one or more of fuse strips
16. This may be accomplished by providing an electrical current of
sufficient magnitude to destroy a fuse section 16, but not so large
as to cause damage to the associated conductive strip 15. For
example, fuse strip 16' may be blown by providing a current of
appropriate magnitude between conductor terminal portion 13b and
conductive strip 15'. The resultant binary permutation code would
consist of three adjacent terminals 15 which are connected to
common conductor 13, and one conductive strip 15' which is
electrically disconnected from common conductor 13. Thus, the key
10 comprises memory means that can be changed to a state offering a
particular binary code permutation that may be detected by
appropriate circuitry such as that described in the aforementioned
U.S. Pat. No. 3,392,558 to R. A. Hedin et al.
While key 10 (FIG. 1) is illustrated as having a coded conductive
pattern 12 on one side only of substrate 11, the invention is not
so limited and both top and bottom faces of substrate 11 could be
provided with coded conductive patterns. Such conductive patterns
may include a separate common conductor on each face of the
substrate, or may utilize a single conductor that extends on both
faces.
A key having a conductor common to both faces is illustrated in
FIGS. 2a and 2b. Referring thereto, a key 19 includes a generally
planar, electrically insulative substrate 20 having a top face 21,
a bottom face 22, a front edge 23 and a rear edge 24. A pattern 25
of electrically conductive strips is formed on substrate 20 by
conventional electronic printed circuitry techniques. Pattern 25
includes a common conductor 26 which extends along rear edge 24 and
overlaps onto both front face 21 and rear face 22. Conductor 26
includes terminal portions 26a and 26b extending on respective
faces 21 and 22 to front edge 23.
Disposed on top face 21 (FIG. 2a) is a first plurality of spaced
parallel conductive strips 27 and 27' each of which initially is
connected to common conductor 26 via a fuse strip 28 analogous to
fuse strip 16 in the key embodiment of FIG. 1. Similarly, bottom
face 22 includes a plurality of conductive strips 29 and 29', each
of which initially is connected to common conductor 26 by means of
a fuse strip 30.
In a manner similar to that described in conjunction with FIG. 1,
selected ones of fuse strips 28 and 30 may be blown to enter in key
19 (FIGS. 2a and 2b) a particular binary permutation code. By
making the associated electronic lock circuitry simultaneously
responsive to the coded contacts on both the top and bottom of key
19, the number of possible combinations of key 19 is considerably
greater than available on a key of the same physical size but
having contacts on one side only.
Alternatively, the electronic circuitry utilized with key 19 (FIGS.
2a and 2b) may be made responsive to the code on only one side
(i.e., either top or bottom) of key 19. Then, by using identical
patterns on the top and bottom, key 19 would operate the electronic
lock regardless of whether top face 21 or bottom face 22 were
inserted in a particular direction (e.g., up or down) with respect
to a key-receiving means.
Key 19 also may be employed in another mode. Specifically,
different codes may be entered on the top and bottom of key 19, and
appropriate circuitry provided so that if key 19 were inserted with
a particular face up, the lock would operate normally. If key 19
were inserted with the same face down, the coding could be such as
to operate the lock while having a further function such as
actuation of an alarm. With such a system, if the key holder were
being forced to enter the controlled area, he could insert the key
"upside down"; the door would open, but at the same time a silent
alarm could be transmitted to a guard or other person.
FIGS. 3a and 3b show one manner in which I construct the key so
that its coding cannot be observed. Thus, a typical key 33
comprises an enclosing member 34 which may be formed of a flexible
plastic or like material. Member 34 includes a pouch portion 35
into which is inserted all of key 33 except its forward portion on
which are front edge 36 and the contact-engaging terminals 37.
Member 34 may be held assembled by an appropriate grommet 36
extending through the substrate of key 33. Member 34 further
includes a flap 38 which encloses terminals 37 when key 33 is not
in use, and which folds back as shown in FIG. 3a to expose
terminals 37 for insertion into key-receiving means of an
electronic lock. Flap 38 may be held closed (FIG. 3b) by a snap
fastener 39.
As an alternative to the enclosing technique just described, the
rearward portion of a key of the type shown in FIGS. 1, 2a or 2b
may be coated with an opaque plastic or like material, leaving
uncoated the front portion and the contact-engaging surfaces of its
key terminals. Conventional identification or credit card
information then may be printed and/or imbedded in the plastic
coating.
A typical example of a combined credit or identification card and
key is illustrated in FIG. 4. Referring thereto, identification
card key 41 includes a key of the type described herein, and
including a substrate or base member 42 having a front edge 43
adjacent to which is situated a plurality of terminals 44. Card key
41 includes a coating 45 on all but the terminal area of substrate
42. Printed or imbedded in coating 41 is conventional
identification card information, possibly including a picture 46
and fingerprint 47 identifying the user. Such indicia is
particularly advantageous for credit card applications, wherein a
merchant can compare the photograph and other identifying
information on the card with the features of the person presenting
the card.
Referring now to FIG. 5, there is shown an embodiment of a key 50
having features like those shown in my earlier copending
application Ser. No. 889,666, including a binary code permutation
of open or closed AC electrical paths. In particular, the key 50
includes a planar, electrically insulative substrate or base member
51 on the surface of which is provided what I term a common
conductor strip 52. Also provided on substrate 51 are a plurality
of spaced terminals 53 and 53' disposed along a front edge 54 of
substrate 51. Terminals 53 and 53' are not directly electrically
connected to conductor 52. Further, key 50 is provided with a pair
of conductive strip terminals 55a and 55b extending from conductor
52 toward front edge 54. Strip terminals 55a and 55b may be used to
complete a DC current path through conductor 52 when inserted into
the key-receiving means of an associated electronic lock.
Referring still to FIG. 5, one or more capacitors 56 are connected
between common conductor 52 and selected ones of the terminals
adjacent edge 54 of key 50. In the embodiment shown, capacitors 56
are connected between conductor 52 and terminals 53'. It should be
apparent that while capacitors 56 complete an AC path between
conductor 52 and respective terminals 53'; neither an AC nor a DC
path exists between conductor 52 and terminals 53. Thus, an AC
signal applied to either of terminals 55a or 55b will be
communicated via capacitors 56 to terminals 53', but will not be
communicated to terminals 53. Nevertheless appropriate electronic
lock circuitry will be responsive to the communicated AC signal and
will detect the permutation code of key 50.
Note that the code of key 50 (FIG. 5) cannot be determined by
measuring DC conductivity between either of terminals 55a or 55b
and the remainder of terminals 53 and 53' due to the fact that the
capacitor will not pass the DC current. Further, to prevent
determination of the code by visual inspection, key 50 can be
encapsulated in plastic, epoxy or the like, to provide a key of the
configuration shown generally in FIG. 6a and 6b. As evident
therein, a key 50' includes encapsulation material 58 covering all
of substrate 51' except for front edge 54' and the terminals
(generally designated 59) adjacent thereto. As indicated in FIG.
6b, encapsulation material 58 completely encloses the capacitors
56' connecting common conductor 52' with selected ones of terminals
59.
Another embodiment of a key for electronic lock or related
application is illustrated in FIG. 7. Shown therein is a key 60
having a planar, electrically insulative substrate 61 forming a
base member atop which are disposed a plurality of memory elements
62. Also disposed on substrate 61 is a common conductor 63
extending in substantially spaced parallel relation with a front
edge 64 of key 60. A conductive strip 63a extends between common
conductor 63 and front edge 64 to form a terminal for conductor 63.
Further, a plurality of spaced parallel conductive strip members
63b extend from conductor 63 to respective ones of memory elements
62. A like plurality of spaced parallel conductive terminal strips
65 extend between respective memory elements 62 and key front edge
64. Another conductive strip 66 extends across key 60, intersecting
each of memory element 62. The ends of conductive strip 66 extend
toward front edge 64 to form terminals 66a and 66b.
The interconnections between memory elements 62, common conductor
63, terminal strips 65 and conductive strip 66 are described
hereinbelow in conjunction with the typical memory elements shown
in FIGS. 9a, 9b, and 10. In general, each memory element 62 may
comprise a magnetic or ferroelectric storage device of either the
destructive or nondestructive readout type. Typically, each memory
element 62 will store one binary digit (bit) of data. The data
stored in memory elements 62 may be readout by providing a read
current along conductive strip 66. When such read current is
provided, an output voltage will appear between common conductor
terminal 63a and those ones of terminal strips 65 associated with
memory elements 62 storing binary 1 bits. Thus, conductive strip 66
and terminal strips 65 are analogous respectively to the word line
and digit drive/sense lines of a conventional magnetic core
memory.
If memory elements 62 are of the destructive type, provision
normally is made in the associated electronic key or related
circuitry to rewrite the stored code back into memory element 62
immediately after reading the same; if nondestructive readout
devices are used for memory elements 62, such rewriting is not
required. Further, means may be provided for altering data in some
but not all of memory elements 62. This is particularly useful when
some of memory elements 62 are used to store an identification code
and the remainder to store date (e.g., funds or credit available in
an account) which may be updated each time the key is used.
Referring now to FIG. 8, there is shown a simplified schematic
diagram of circuitry for utilizing the key of FIG. 7. Specifically,
there is a key receptacle 70 that may be like the one shown in u.s.
pat. No. 3,392,558, including a slot 71 into which the front
portion 64 of key 60 is inserted. Within key receptacle 70 are a
plurality of contacts 72 which engage and make electrical contact
with terminal strips 65 of the inserted key 60. Additional contacts
72a, 72b, and 72c respectively engage terminal 66a, 66b and 63a of
key 60. A cable 73 electrically interconnects the contacts of key
receptacle 70 with conventional read/write circuitry 74. Circuitry
74 may be of the type commonly used to enter data into, or read
data from magnetic core memories.
The data read by circuitry 74 from memory elements 62 is provided
via a line 75 to key code recognition circuitry 76. Circuitry 76
produces an output along a line 77 whenever the code read from a
set of memory elements 62 corresponds to a code preset in code
recognition circuitry 76. Thus the occurrence of a signal on line
77 indicates that the correct key has been inserted in key
receptacle 70.
The signal on line 77 is provided to a utilization device 78 which,
in the case of an electronic lock, may comprise an electric door
latch. In a credit card type application, the code contained in
some but not all of memory element 62 on key 60 may represent the
credit card number, and code recognition circuitry 76 may be
programmed to determine if the credit card number is a valid
one.
In such credit card applications, utilization device 78 may include
a computer for determining the amount of credit or funds still
available to the credit card holder. Alternatively, others of
memory elements 62 may store data indicating the balance of funds
or credit available to the credit card holder. In this case,
utilization device 78 could add or subtract the amount of the
credit card transaction from the previous balance stored on the
key. The new balance then may be transmitted via line 79 (FIG. 8)
to read/write circuitry 74 for entry of the new credit balance into
key 60.
FIG. 9a shows a first embodiment of a memory element 62, comprising
a conventional annular magnetic core 81. As is well known, such a
magnetic core 81 has a substantially square hysteresis loop,
representing two stable magnetic states. Thus if core 81 is set to
the magnetic state representing a binary 1, the core will remain in
this state until switched to the alternate state by subsequent
application of an appropriate magnetic field.
Referring to FIG. 9a, core 81 is threaded by a first wire 82
extending between segments of conductive strip 66. A second wire 83
also is threaded through core 81, and extends between conductive
strip 63b and terminal strip 65.
To enter data into a core 81 which is preset to the binary 0 state,
a write current is provided between terminal 66a and 66b (FIG. 7);
this current flows through wire 82. Typically, the write current
will be selected so that the resultant magnetic field about wire 82
is insufficient to magnetize core 81 to the binary 1 state. If it
is desired to set core 81 to the binary 1 state, another current
simultaneously is provided between terminal 63a and the terminal
strip 65 associated with the particular core 81 to be so set. The
resultant current through conductor 83, together with the write
current through conductor 82, produce a net magnetic field which is
sufficient to set core 81 to the one state. Alternatively, if a
binary 0 is to be set, no current is provided through wire 83.
Since the write current through wire 82 itself is insufficient to
flip core 81 from the 0 state to the 1 state, the core remains set
at binary 0.
To read data from core 81, a read current is applied between
terminals 66a and 66b. This read current, which flows through wire
82, is of appropriate magnitude and direction so that the resultant
magnetic field will cause core 81 to flip into the zero state. If
core 81 contains a binary 0, its magnetic state will not change
when the read current is applied, and no voltage will be induced in
wire 83. Alternatively, if core 81 contains a binary 1, application
of the read current through wire 82 will cause core 81 to flip from
the binary 1 to the binary 0 state, inducing a signal in wire 83.
This induced signal will appear between terminals 63a (FIG. 7) and
the terminal strip 65 associated with the particular core 81. The
presence or absence of such an induced signal at each of terminals
65 of key 60 (FIG. 7) thus is indicative of the data stored in
corresponding memory elements 62.
Readout of core 81 (FIG. 9a) is destructive. That is, upon readout
core 81 is set to the 0 state regardless of whether a binary one or
binary 0 had been stored therein. Accordingly, external circuitry
is necessary to rewrite the data back into core 81 if the same data
is to be maintained therein. The value of a destructive readout may
be appreciated when it is understood that a key thereby may be
limited to one useful operation, so that a person possessing the
key may have merely a single access to the electronic apparatus.
Also, the apparatus if so aligned may readily apply a different
code to the key. In contradistinction, the magnetic core element
illustrated in FIGS. 9b offer nondestructive readout. That is, data
in the core can be sensed without disturbing or destroying data
contained therein.
In FIG. 9b, a two-apertured magnetic core 85 is employed. Threading
the large and small apertures 85a and 85b of core 85 is a
sense/write wire 87. Wire 87 is connected between segments of
conductive strip 63b and terminal strip 65 so that a sense/write
signal provided or generated between terminal 63a and a terminal
strip 65 (FIG. 7) will flow through wire 87. A read wire 86,
connected between segments of conductive strip 66, threads through
small aperture 85b in core 85. When a read current of appropriate
magnitude is provided through wire 86, a voltage is either induced
or not induced in wire 87, depending on whether core 85 is storing
respectively a binary 1 or a binary 0. In either case, the magnetic
state of core 85 is not switched by application of the read
current; that is, readout is nondestructive and the data bit stored
in core 85 subsequently can be reaccessed from the core.
FIG. 10 shows an exemplary thin film memory element 95 which may be
employed as a memory element 62 in the key of FIG. 7. Memory
element 95 is formed on a substrate 96 which could either
correspond to substrate 61 of key 60 or, alternatively, could be a
separate substrate that is subsequently attached to key 60. Formed
on substrate 96 is a first magnetic film 97, disposed atop which is
a conductive word line 98. Magnetic film 97 is oriented so that the
easy axis of magnetization is parallel to word line 98. Further,
word line 98 may be connected in series with segments of conductive
strip 66 on key 60 (FIG. 7).
Still referring to FIG. 10, memory element 95 includes an
insulation layer 99 separating the top of word line 98 from a
conductive digit sense/line 100. Digit/sense line 100 itself is
perpendicular to word line 98 and may be connected electrically
between a conductive strip 63b and a terminal strip 65 of key 60
(FIG. 7). Another insulation layer 101 separates conductor 100 from
a second magnetic film 102. Again, the easy axis of magnetization
of magnetic film 102 is oriented parallel to word line 98, and
perpendicular to digit/sense line 100. Finally, a protective,
electrically insulating substrate 103 is disposed atop magnetic
film 102.
In planar magnetic films, such as those employed in memory element
95 (FIG. 10) the flux is rotated rather than switched, thereby
affording high speed operation. Data may be readout of memory
element 95 by applying an appropriate read current along word line
98. An output signal, indicative of the data stored in memory
element 95, is induced on digit/sense line 100.
Yet another embodiment of a key for an electronic lock is
illustrated in FIG. 11. As seen therein, a key 105 includes a
planar, electrically insulative substrate 106 having a front edge
107. Disposed atop substrate 106 is a common conductor 108 having a
generally L-shaped configuration, including a terminal portion 108a
extending toward edge 107. A plurality of spaced parallel terminal
strips 109 are disposed atop substrate 106 adjacent front edge 107.
Mounted on substrate 106 is a like plurality of plated wire
magnetic memory elements 110. Each element 110 includes a central
conductor wire 111 connected between conductor 108 and a respective
one of terminal strips 109.
Also disposed on substrate 106 of key 105 (FIG. 11) are a pair of
terminal strips 112a and 112b. Electrically connected in series
between terminal strips 112a and 112b is an insulated wire 113
which functions as a word line for memory elements 110. Insulated
wire 113 is woven about each of memory elements 110. When a current
is applied between terminal strips 112a and 112b, the magnetic
field induced by woven word line 113 causes output signals to be
generated by those memory elements 110 which are storing binary
ones. These output signals appear at the corresponding ones of
terminals 109. No such outputs are produced by memory elements 110
in which binary zeros are stored. As in the other key
configurations described herein, the coding of the key is
represented by the permutation of binary digits stored in memory
elements 110.
A further form of key for an electronic lock is shown in FIG. 12.
In this embodiment, a key 115 incorporates a diode matrix which is
capable of providing a particular binary permutation code output in
response to application of a multibit interrogation code.
As indicated diagrammatically in FIG. 12, key 115 comprises a
substantially flat, electrically nonconductive base member or
substrate 116 having a top surface 116a, a bottom surface 116b and
a front edge 117. Disposed in spaced parallel relation on substrate
top surface 116a, perpendicular to edge 117, is a first plurality
of conductive strips 118, 118a, 118b which serve as column
conductors for the diode matrix. Disposed on substrate bottom
surface 116b is a second plurality of conductive strips 119, 119a,
119b which form row conductors for the matrix. A set of diodes 120,
120a, 120b are electrically connected between selected
intersections of row conductors 119 and column conductors 118. For
example, diode 120a is electrically connected between column
conductor 118a and row conductor 119a. Similarly, diode 120b is
electrically connected between column conductor 118b and row
conductor 119a.
It will be appreciated that when a voltage is applied to one of row
conductors 119, a corresponding output voltage will appear only on
those of column conductors 118 which are diode connected to the
energized row conductor. Thus if a voltage were applied only to row
conductor 119a, an output voltage will appear only on column
conductors 118a and 118b; no output voltage will appear on the
others of column lines 118. Similarly, a different binary output
permutation will be produced on column lines 118 if a voltage is
supplied to one of the other row conductors 119. Thus, diode matrix
key 115 could be used to store information of different
significance in different matrix rows. For example, the binary
permutation code associated with row 119a may represent a credit
card number, while information along row 119b may represent a
maximum amount of credit available.
Alternatively, note that a voltage could be applied simultaneously
to several of the row conductors 119, and that the resultant binary
permutation output code appearing on column conductors 118 would be
a function of (a) the particular ones of row conductors 119
receiving a voltage input, and (b) the specific configuration of
diodes 120 in the matrix. Thus, key 115 could be accessed with a
multibit interrogation code applied to row conductors 119, and
would produce a particular output code only if the diode matrix
were correctly configured. With this type of operation, an
extremely large number of information combinations (i.e., binary
permutation codes) would be available on key 115.
The diode matrix of FIG. 12 may be constructed by utilizing
discrete diodes mounted through holes in substrate 116 at the
appropriate intersections between row conductors 119 and column
conductors 118. Alternatively, the diode array may be in the form
of integrated circuit fabricated with diodes at each matrix
intersection. To code the matrix, at intersections where no diode
is desired, the prefabricated diode may be blown or otherwise open
circuited by application of a sufficiently large current. Another
possibility is to fabricate the array with diodes only at certain
preselected matrix intersections.
FIG. 13 illustrates a key employing an integrated circuit diode or
transistor matrix. As indicated therein, a key 122 includes a
planar, electrically insulative substrate 123 having a front edge
124. The diode or transistor matrix array is housed in a
"flat-pack" 125 mounted on the surface of substrate 123. Electrical
connections to the row conductors of the matrix are provided by a
plurality of conductive strips 126 disposed on the same surface of
substrate 123 and extending to front edge 124 thereof. Similarly,
electrical connections to the column conductors of the matrix are
provided via a plurality of spaced parallel terminal strips 127
disposed on the same surface of substrate 123 and also extending to
front edge 124 thereof. When using a transistor matrix, an
additional voltage connection is made to the matrix by means of a
conductive strip 128 also provided on the same surface of substrate
123.
FIG. 14 is an electrical schematic diagram of a transistor matrix
which may be utilized in key 122 of FIG. 13. In particular, matrix
array 130 includes a plurality of bipolar transistors 131 arranged
in a matrix of rows and columns. The collectors of all transistors
in the array are electrically connected to a common conductor 132
to which is supplied a voltage via conductive strip 128 of key 122
(FIG. 13).
Transistor array 130 (FIG. 14) also includes a first plurality of
row conductors 133 and a second plurality of column conductors 134
which may be conducted respectively to conductive strips 126 and
terminal strips 127 of key 122 (FIG. 13). The base of each
transistor 131 is connected to its respective row conductor 133 by
means of a resistor 135. Further, the emitters of selected ones of
transistors 131 are electrically connected to the respective column
lines 134 via conductive links 136. The emitters of the remainder
of transistors 131 are not connected to an associated column line
134, as indicated by missing links 137. The particular selected
array of links 136 and missing links 137 may be provided by
appropriate masking during fabrication of transistor matrix
130.
It will readily be appreciated that when an interrogate voltage is
supplied on one of row lines 133, each of transistors 131 in the
corresponding interrogated row will be turned on. Accordingly, a
collector voltage supplied on line 132 will appear on those of
column lines 134 to which transistors 131 in the interrogated row
are connected by means of links 136. No such voltage will appear on
the remainder of the column lines 134.
As in the case of the diode array described hereinabove, the matrix
rows may be interrogated individually or, alternatively, a multibit
interrogate code may be applied simultaneously to all of row lines
133 to produce a unique output code along column lines 134.
Further, while FIG. 14 is shown to incorporate bipolar transistors,
this is not required, and metal oxide semiconductor field effect
transistors (MOS FET's) or other transistor types could be
employed.
Another key for an electronic lock, the binary permutation code of
which may be sensed magnetically, is shown in FIG. 15.
Specifically, a key 140 comprises a planar, electrically
insulative, nonmagnetic base member or substrate 141. Disposed at
selected locations on the surface of substrate 141 are a plurality
of electrically conductive circular strips or eddy current rings
142.
As is well known, when an annular wire or conductive strip is
exposed to a changing magnetic field, an eddy current will be
induced in the annulus. The eddy current itself will produce a
counter magnetic field which tends to oppose the change in the
field inducing the eddy current. Thus, the presence or absence of
an eddy current ring 142 at a particular location on substrate 141
may be sensed by applying a changing magnetic field at that
location, and determining whether the magnitude of the field is (a)
changed, indicating the presence of an annular conductive strip
142, or (b) unchanged, indicating the absence of an eddy current
ring. By simultaneously or sequentially determining the presence or
absence of eddy current rings 142 at a plurality of locations on
the key 140, the binary permutation code of key 140 can be
sensed.
An optical key for an electronic lock is illustrated in FIG. 16. As
shown therein, key 145 includes a substrate 146 having an aperture
147 therein. Disposed across aperture 147 is an optical mask 148
comprising a matrix of opaque spots 149 and transparent spots 150.
The coding of key 145 is determined by the particular locations of
opaque spots 149.
Apparatus for detecting the particular code of key 145 is
illustrated in FIG. 17. As seen therein, key 145 is inserted
between a light source 152 and an end 153 of a fiber optic bundle
154. At the other end 156, the various fibers of bundle 155 are
fanned out and directed to individual photodetectors 157. The
outputs of photodetectors 157 are connected to appropriate
electronic lock circuitry 158.
In operation, the transparent spots 150 of optical mask 148 will
permit light from source 152 to enter the fibers in corresponding
positions in fiber optic bundle 155. The light entering these
fibers will be transmitted to bundle end 156 and impinge on the
associated photodetectors 157. These photodetectors will provide an
output signal to lock circuitry 158. The opaque spots 149 will
prevent light from source 152 from entering others of the fibers in
fiber optic bundle 155. Accordingly, those of photodetectors 157
associated with nonilluminated fibers will provide no output
signals to lock circuitry 158. Thus, the permutation of signals and
no signals from photodetectors 157 will be indicative of the
orientation of opaque spots 149 and transparent spots 150 in
optical mask 148. Lock circuitry 158 may be prewired to be
responsive only to a particular optical code included in mask 148
of key 145.
While the invention has been described with respect to the
preferred physical embodiments constructed in accordance therewith,
it would be apparent to those skilled in the art that various
modifications and improvements may be made without departing from
the scope and spirit of the invention.
* * * * *