U.S. patent number 3,609,741 [Application Number 04/809,259] was granted by the patent office on 1971-09-28 for prevention of unauthorized movement of articles between predetermined areas.
Invention is credited to Wendell S. Miller.
United States Patent |
3,609,741 |
Miller |
September 28, 1971 |
PREVENTION OF UNAUTHORIZED MOVEMENT OF ARTICLES BETWEEN
PREDETERMINED AREAS
Abstract
A system for indicating an attempt to move an article, such as a
piece of baggage or an article of merchandise, between
predetermined areas, by providing a radio transmitter and radio
receiver between the areas, and providing on the article a device
having electrical circuitry adapted to receive from the transmitter
a signal at a first frequency, and retransmit a radio signal of
changed frequency, with the receiver being constructed to respond
to and indicate the presence of the return signal. A person
authorized to move the baggage or other article may have a key
adapted to disable the circuitry against transmission of the
changed frequency signal, or otherwise alter the signal, in a
manner indicating to the receiver his authorization.
Inventors: |
Miller; Wendell S. (Los
Angeles, CA) |
Family
ID: |
25200900 |
Appl.
No.: |
04/809,259 |
Filed: |
March 21, 1969 |
Current U.S.
Class: |
340/568.1;
340/572.3; 342/51; 340/10.41; 455/19; 340/5.64 |
Current CPC
Class: |
G08B
13/14 (20130101) |
Current International
Class: |
G08B
13/14 (20060101); G08b 013/14 () |
Field of
Search: |
;340/152TR,312,258,280,276,224,420,421,171 ;325/8,16,21,29 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Caldwell; John W.
Assistant Examiner: Bobbitt; J. Michael
Claims
While certain specific embodiments of the present invention have
been disclosed as typical, the invention is of course not limited
to these particular forms, but rather is applicable broadly to all
such variations as fall within the scope of the appended
claims.
1. Apparatus for detecting an attempted unauthorized movement of an
article between two areas, comprising means for transmitting a
first radio signal at or near said areas, circuitry carried by said
article responsive to said first signal and operable to transmit a
second and different radio signal, means responsive to said second
signal and operable to indicate whether an attempted movement of
said article is authorized, and a control key device which is
separable from said article and is adapted to alter the response of
said circuitry to said first signal in a manner which may be sensed
by said last mentioned means to indicate that a person having the
key device is authorized to move the article.
2. Apparatus as recited in claim 1, in which said circuitry in a
predetermined normal condition is responsive to said first signal
to produce said second signal, said control key device being
operable to disable the circuitry against transmission of said
second signal.
3. Apparatus as recited in claim 1, in which said circuitry
includes an antenna for receiving said first signal, a rectifier
for producing said second signal from said first signal at a
frequency which is a harmonic of the frequency of the first signal,
and an antenna for emitting said second signal, said key device
being movable to a predetermined position relative to said
circuitry and operable to short circuit said circuitry in a
relation preventing transmission of said second signal, there being
means on said article defining a receptacle for removably retaining
said key at said position.
4. Apparatus as recited in claim 1, in which said circuitry
includes an antenna for receiving said first signal, a rectifier
for rectifying the received first signal to produce an output of
doubled frequency, and a transmitting antenna for transmitting said
second signal at said doubled frequency.
5. Apparatus as recited in claim 1, including holder means for
removably receiving and holding said key device at a predetermined
active position in which its presence has an effect on said second
signal.
6. A device for detecting an attempted unauthorized movement of an
article between two areas, comprising a structure to be carried by
the article and having circuitry adapted to receive a first radio
signal from a transmitter at or near said areas, and responsive to
said first signal to produce a second and different radio signal
for indicating by said second signal whether an attempted movement
of the article is authorized, and a control key device which is
separable from said structure and adapted to be carried by an
authorized person and is adapted to alter the response of said
circuitry to said first signal in a relation indicating that the
person is authorized.
7. A device as recited in claim 6, in which said circuitry is a
transponder circuit utilizing the received power of said first
signal to produce said second signal.
8. A device as recited in claim 6, including holder means for
removably receiving and holding said key device at a predetermined
active position in which its presence has an effect on said second
signal.
9. A device as recited in claim 6, in which said circuitry includes
antenna means for receiving said first signal, rectifier means for
rectifying said first signal and producing said second signal at a
frequency which is a harmonic of the frequency of the first signal,
and antenna means for emitting said second signal, there being a
socket for removably receiving said key device, said key device
being operable when in said socket to disable said circuitry
against production of said second signal.
10. The combination comprising an article which may be removed from
a predetermined area, and a device carried by said article for
indicating an attempted unauthorized removal of the article from
said area, said device including circuitry adapted to receive a
first radio signal from a transmitter at or near said area, and
responsive to said first signal to produce a second and different
radio signal for indicating by said second signal whether an
attempted removal of the article is authorized, and a control key
which is separable from said device and is adapted to alter the
response of said circuitry to said first signal in a relation
indicating that a person having said key is authorized.
11. The combination as recited in claim 10, in which said article
is an article of baggage.
12. The method of detecting an attempted unauthorized movement of
an article between two areas, comprising requiring said article to
be carried past a detection station if it is moved between said
areas, transmitting a radio signal to said article as it passes
said station, providing the article with circuitry responsive to
said transmitted signal and operable to transmit a second radio
signal, monitoring said second signal as an indication of whether
an unauthorized movement of the article is being attempted,
applying a key to said circuitry if movement of said article is
authorized, changing the condition of said circuitry by use of said
key, and detecting said change in condition of the circuitry
through a change in said second signal.
13. Apparatus for detecting an attempted unauthorized movement of
an article between two areas, comprising circuitry carried by said
article and operable to transmit a radio signal which is to be
monitored by a receiver and which indicates whether said movement
of the article is authorized, and a key which is separable from
said article and is adapted to alter the transmission of said radio
signal in a manner which may be sensed by said receiver to indicate
that a person having the key is authorized.
14. The method of detecting attempted unauthorized movement of any
of a number of articles between two ares, comprising requiring said
articles to be carried past a detection station upon such movement,
monitoring radio signals received from circuitry carried by said
articles as they are moved past said station, converting said
circuitry of any article authorized for said movement to a
condition different from that of any articles not authorized for
said movement by means of keys carried by authorized persons and
separable from said articles, and distinguishing between said
authorized and unauthorized articles by differences in said
monitored radio signals.
15. Apparatus for controlling movement of an article between two
areas; comprising means to be located at or near said areas and
operable to transmit a first radio signal to circuitry carried by
said article; means for receiving a response signal from said
circuitry and determining therefrom whether or not said movement of
the article is authorized; a turnstile or other movement
controlling structure between said areas; and means controlling
operation of said turnstile or other movement controlling structure
in correspondence with changes in said response signal.
16. The method of detecting an attempted unauthorized movement of
an article between two areas, comprising requiring said article to
be carried past a detection station if it is moved between said
areas, transmitting a radio signal to said articles as it passes
said station, providing the article with circuitry responsive to
said transmitted signal and operable to transmit a second radio
signal, monitoring said second signal as an indication of whether
an unauthorized movement of the article is being attempted, and
applying to said circuitry a third radio signal intense enough to
purposely destroy its capacity to produce said second signal, if
said movement of the article is to be authorized.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to apparatus and methods for
indicating whether a particular person is authorized to move a
certain piece of baggage or other article between two different
areas.
In the baggage room of an airport or the like, great difficulty is
encountered in attempting to maintain any effective control against
unauthorized removal or theft of a suitcase from the area. Large
numbers of bags frequently arrive at the pickup zone
simultaneously, and must be distributed to many different travelers
in a very short period of time with minimum inconvenience to the
travelers. Attempts to compare check numbers at an exit location
have resulted is such excessive slowing of the overall rate of
movement of baggage and persons through the area that in many
airports all such attempts at checking have been abandoned.
Similarly, in a store or other establishment having merchandise or
other articles on display at accessible locations, it is very
difficult to detect an attempt at removal of an article from the
store or from a particular area of the store. The article may be
completely concealed by the taker within a handbag, box, piece of
clothing, or the like, in a manner rendering it almost impossible
to detect the article as it is carried from the store.
SUMMARY OF THE INVENTION
The present invention provides apparatus and methods for indicating
very rapidly and conveniently whether a person who is attempting to
move a particular article, such as a suitcase, item of merchandise,
identification badge, or the like, between two areas, is authorized
for such movement. The indication of authorization or
nonauthorization may be given in any desirable manner, as by an
audible or visual signal, by opening or closing a door or gate at
an exit or entrance location, or in any of numerous other ways.
The desired monitoring result is attained by providing radio
equipment at or near the controlled area which coacts with a very
simple device on the bag or other article in a manner giving the
indication of authorization or nonauthorization. The circuit on the
article may be a miniaturized extremely low cost integrated
circuit, which may be energized completely by power received from
the primary radio equipment near the exit location, without the
necessity for provision of a supplementary power source on the
individual articles being controlled.
In applying the present invention to the control of baggage and
certain other types of articles, I preferably provide in
conjunction with the circuitry on the bag a control unit or control
means which is actuable only by an authorized person, and which
upon actuation will indicate to the fixed radio equipment that the
person is authorized. For example, this control unit may take the
form of a key which is carried by the authorized person, and is
capable of converting the circuitry on the bag or other article to
a condition indicating authorization of the person using the key.
Alternatively, a combination lock or other control unit may be
substituted for the key.
For maximum simplicity, the circuitry carried by the article being
controlled desirably constitutes a transponder circuit which is
adapted to receive a radio signal of predetermined frequency from a
fixed transmitter at the exit location, and which then transmits a
response signal at a changed frequency to which the fixed receiver
is tuned. In most instances, the frequency emitted by the
transponder circuitry may be a multiple or harmonic of the original
received frequency, in which event a simple rectifier circuit may
function to change the frequency. It is also contemplated, however,
that other frequencies may be emitted by the transponder, such as a
subharmonic frequency or a nonharmonic frequency produced by a
heterodyne circuit in the transponder in which two frequencies
received from the main transmitter are mixed to produce sum and
difference frequencies.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features and objects of the invention will be
better understood from the following detailed description of the
typical embodiments illustrated in the accompanying drawing, in
which:
FIG. 1 is a diagrammatic representation of an airport baggage area,
or other area to which the invention is to be applied;
FIG. 2 illustrates fragmentarily in perspective a suitcase which
may be located within the baggage area of FIG. 1, and which carries
a response circuit for indicating when an attempt is made to remove
the bag by an unauthorized person;
FIG. 3 is a greatly enlarged fragmentary section taken on line 3--3
of FIG. 2, and showing a key positioned within the bag carried
device of FIG. 2;
FIG. 4 illustrates diagrammatically the circuitry of the bag
carried device;
FIG. 5 shows the preferred wave form of the two radio signals
utilized in the apparatus; and
FIG. 6 shows a variational form of the invention which is adapted
for attachment to an article of merchandise, and which may not be
key actuated .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the FIG. 1 diagram, a room or area to be policed by equipment
embodying the present invention is illustrated generally at 10,
being bounded by walls 11, and typically having entrance 12 through
which persons may enter the room, and an exit opening or doorway 13
through which persons leave the room. As exemplary of one preferred
use of the invention, the room or area 10 may be considered as
constituting a baggage reception area in an airport or the like,
having a conveyor represented at 14 along which the individual bags
15 are advanced into the room and onto a support surface or
platform 16 from which the individual tourists may select their
various bags. After a person has obtained all of his baggage from
the platform 16, he leaves the room through exit 13, and in doing
so must pass certain stationary equipment 17 positioned adjacent
the exit doorway for determining whether the person attempting to
remove a particular piece of baggage is authorized to do so. For
coaction with the stationary equipment 17, individual pieces of
baggage are provided with a transponder unit 18 (FIGS. 2 and 3)
which is preferably controlled by a key 19 kept in the possession
of the person owning the bag.
The fixed equipment 17 adjacent or near exit 13 includes a radio
transmitter 20 which emits a preferably continuous and unchanging
radio wave of a predetermined frequency, desirably a frequency
within one of the industrial bands. In FIG. 5 the sinusoidal
voltage curve of that wave emitted by transmitter 20 is represented
at 21. Also near or adjacent exit opening 13 there is provided a
stationary radio receiver 22 (FIG. 1), which is tuned to receive
and respond to a radio wave of a predetermined frequency different
than that emitted by transmitter 20. Preferably, receiver 22 is
responsive only or primarily to a radio wave whose frequency is a
predetermined multiple or harmonic of (desirably the second
harmonic of) the radio wave emitted by transmitter 20. An
indicating unit 23 is controlled by receiver 22 and is energized to
produce an appropriate indication when a signal of the
predetermined harmonic frequency is received by receiver 22. The
indicator unit 23 may typically be a horn, bell, or other audible
signal, a light, sign or other visual signal, or any other type of
indicator whose energization indicates to an attendant that a
particular person carrying a bag past transmitter 20 and receiver
22 is not authorized to do so. Alternatively or supplementally, the
indication of authorization or nonauthorization may be given by
automatic actuation of a turnstile 24 or other gate structure at
the exit location between passing and nonpassing conditions, under
the control of receiver 22 in accordance with its reception or
nonreception of the predetermined harmonic frequency. It is
contemplated that the indications given by the system may function
in any of numerous manners, to indicate by energization of the
audible or other signal either that the person is authorized or not
authorized, as desired, and either to actuate a turnstile or gate
from a normally open or passing condition to a closed or nonpassing
position when an unauthorized person attempts to leave the area, or
alternatively to actuate a normally closed or nonpassing turnstile
or gate to an open or passing condition when an authorized person
desires to leave.
The transponder units or devices 18 carried by the individual bags
15 are designed to receive the radio signals emitted by transmitter
20, and to respond thereby to transmission of a changed radio
signal of the particular type to which receiver 23 is tuned. As
previously indicated, this signal to which the receiver is tuned is
preferably a harmonic of the signal received by device 18 from
fixed transmitter 20, for best results the second harmonic. To
produce the second harmonic, the device 18 may rectify the signal
from transmitter 20, as represented by the sinusoidal wave 21 of
FIG. 5, to the pulsating direct current condition illustrated at 25
in FIG. 5, in which the frequency of pulsating wave 25 is twice
that of wave 21. The full wave rectified current is then passed
through a transmitting antenna to transmit a radio wave from the
device 18 to receiver 22 at the second harmonic frequency.
FIG. 4 shows schematically at 26 a typical electrical circuit for
the device 18. This circuit includes a receiving antenna coil
represented at 27, which feeds into a bridge-type full wave
rectifier circuit 28, whose rectified output in the form of
pulsating direct current as represented at 25 in FIG. 5 is passed
through a transmitting antenna coil 29. The rectifier circuit
includes four individual rectifier elements 30, typically of the
solid-state variety.
Structurally, the entire circuit 26 illustrated in FIG. 4 may be
formed as a very inexpensive highly miniaturized integrated
circuit, formed on a single typically rectangular very thin and
small chip 31 of silicon or the like, on which the various
components are formed by appropriate painting or deposition
techniques (see FIG. 3). More particularly, the antenna coils 27
and 29 may be painted on the silicon body 31 as thin lines of
aluminum paint or other conductive material extending about the
silicon ship and along its outer surface. The diodes or rectifiers
30 may be formed by appropriately doping localized portions of the
surface of the silicon with "N" and "P" material, as at the
locations designated 30 in FIG. 3. The electrical connections
between the various parts, like the coils, are formed by aluminum
or other conductive lines painted on the surface of chip 31. The
chip 31 and its circuitry elements may be completely encapsulated
within a molded body 32 of electrically insulative material, such
as a suitable resinous plastic material, defining an insulative
wall 33 at the underside of the circuitry elements engageable with
the outer surface of the suitcase, and defining a wall 34 at the
upper or outer side of the chip 31 and its carried circuit. This
encapsulating insulative body 32 may have flanges extending about
its periphery at 35, secured to the suitcase by fasteners 36 or
otherwise. It is also contemplated that the device may be secured
to the suitcase by adhesive, or in any other convenient manner.
Above wall 34 formed by the insulative encapsulating material, this
material forms and defines an elongated slot 37, which is opened
only at its left end 38, and into which the previously mentioned
key 19 is slidably receivable in the closely confined and
accurately located relation illustrated in FIG. 3. This key is
normally in the possession of the owner of the suitcase, and is
inserted into slot 37 at the time that the owner receives his bag
from support platform 16 of FIG. 1, to thereby place the device 18
in a condition for indicating to the radio equipment 17 at the exit
opening 13 that the person carrying the bag is authorized to remove
it from the area.
In the particular arrangement illustrated in FIG. 3, the key 19 is
assumed to be formed of an electrically insulative material, such
as a suitable rigid resinous plastic material, except at the
location of two electrically conductive metal inserts 39 and 40.
These inserts are engageable with contacts 41, 42, 43 and 44
projecting upwardly from the circuitry formed on integrated circuit
chip 31, so that when the key is in the FIG. 3 position, metal
element 39 will engage and form a short circuit between contacts 41
and 42, while element 40 will engage and form a short circuit
between contacts 43 and 44. From the schematic representation of
FIG. 4, it will be apparent that the contacts then form short
circuits across both of the antenna coils 27 and 29, and thereby
disable circuit 26 against functioning as a transponder in the
previously discussed manner. The circuit 26 will then not serve to
transmit any radio signal in response to reception of the signal
from fixed transmitter 20.
To now recapitulate the manner of use of the device illustrated in
FIGS. 1 to 4, assume that transmitter 20 is functioning
continuously to emit a radio signal of a predetermined radio
frequency, and that receiver 22 will respond only to the second
harmonic of that frequency. Also assume that the various bags 15
being delivered onto platform 16 from conveyor 14 are provided with
transponder devices of the type illustrated at 18, but that these
devices are ineffective to transmit any substantial detectable
signal to receiver 22 when the bags are in the right-hand portion
of the room 11 of FIG. 1. The transmitter 20 may if desired be made
directional, to aim its transmission primarily across the exit
doorway in the direction indicated at 45 in FIG. 1, while the
antenna of receiver 22 may be made similarly directional to receive
radio signals best and primarily in the direction indicated at 46
in FIG. 1. Also, the intensity of the transmitted signal, the
sensitivity of receiver 22, and the components of circuit 26 of the
transponder devices 18 may all be so selected and designed as to
enable the receiver 22 and indicator 23 to respond only to the
devices 18 individually, as each separate bag is carried out of the
exit opening 13.
If an unauthorized person picks up one of the bags 15 from the
location as and attempts to carry it from the room through exit
opening 13, the signal emitted by transmitter 20 will be received
by antenna 27 of the device 18 on that particular bag, will be
rectified by the full wave rectifier 28, and will cause
transmission of a response signal of doubled frequency from antenna
29 to receiver 22. The receiver in turn will energize indicator 23
to emit an audible or visual signal, or the like, indicating to an
attendant that an unauthorized removal of the bag has been
attempted. If the person is the true owner of the bag, on the other
hand, he merely inserts key 19 into slot 37 of FIG 3, to form a
short circuit across both of the coils 27 and 29 in a manner
disabling the circuit, As previously described, so that device 18
cannot transmit the harmonic frequency signal, and indicator 23 is
not actuated. The receiver 22 is of course tuned accurately to the
harmonic frequency, and includes filter circuits which filter out
the fundamental frequency of transmission of the transmitter 20,
and all other unwanted frequencies, so that there is no response of
the receiver and indicator unless the precisely predetermined
harmonic frequency is received. Also, transmitter 20 must be
filtered effectively to produce a pure fundamental frequency,
without harmonics, so that the signal from the transmitter cannot
in any way serve to directly actuate the receiver, without the
interaction of frequency doubling transponder device 18.
Instead of disabling the circuitry, the key 19 or its equivalent
may upon insertion serve to convert the circuit from a disabled
condition to an active condition, to transmit a signal for
reception by receiver 22 only when the key is inserted, and thereby
indicate authorization rater than nonauthorization of the person.
Also, as previously indicated, the signals received by receiver 22
may control the operation of the turnstile, to either allow a
person to leave the area, or prevent his leaving, in accordance
with the reception of a control signal by receiver 22 from device
18.
FIG. 6 shows a variational device which may be utilized for
indicating an attempt to remove from a store or other area an
article 15a, which may typically be an article of merchandise
displayed for sale in the store. The device 18a of FIG. 6 may be
very similar to transponder device 18 of FIGS. 1 to 4, except for
the deletion of key 19 and the contacts to be engaged thereby. The
integrated circuit 26a of FIG. 6 may be otherwise identical with
circuit 26 of FIG. 4, and may be formed on a silicon chip such as
that illustrated at 31 in FIG. 3, and be completely encapsulated
within an electrically insulative material 32a. The encapsulated
unit is adapted to be attached in any suitable manner to the
article of merchandise 15a or other article, as by provision of a
layer of pressure sensitive adhesive 47 on one surface of the
capsule, and/or by provision of a flange or tab 48 on the capsule,
typically containing an opening 49 by which the capsule may be
pinned or otherwise fastened to an article of clothing or other
piece of merchandise to be protected.
When an unauthorized person attempts to remove the article 15a from
the selling area or room, he must in leaving the room pass a
transmitter such as that shown at 20 in FIG. 1, a receiver 22,
indicator 23, etc. Upon reception of the signal emitted by
transmitter 20 the device 18a of FIG. 6 will transmit a response
signal of doubled or other harmonic frequency serving to actuate
the indicator 23 or other unit serving as an alarm for apprising an
attendant of the attempted theft. When an article carrying one of
the devices 18a is sold, a sales person may remove the transponder
device 18a, or alternatively may merely bring the device near a
highly powered transmitter represented diagrammatically at 50 in
FIG. 6, in a manner such that the radio signal emitted by
transmitter 50 will produce in the coils 27a and 29a of the
integrated circuit in device 18a a current so great as to purposely
burn out or destroy one or more of the diodes 30 or other
components of the integrated circuit, and thereby disable it in a
manner such that it will not subsequently actuate the alarm system
when the purchaser passes the transmitting equipment upon leaving
the sales area.
The device 18a of FIG. 6, or other variations of the invention, may
also be used on or as identification badges, to be worn or carried
by persons in a manufacturing plant or the like, for indicating
whether these persons are authorized to enter or leave a particular
area policed by a transmitter, receiver, etc., as shown in FIG. 1.
In that case, the identification badge or the device 18a itself
becomes the article whose movement between areas is either
authorized or unauthorized, and is to be controlled by the
monitoring equipment.
* * * * *