US 3766452 A
Disclosed is an instrumented token or chip representative of value. Concealed within or on the surface of the token is a passive resonant circuit which responds to incident electromagnetic radiation in a preselected frequency to produce and radiate a unique detectable signal indicative of the token's presence in the incident field.
Description (OCR text may contain errors)
United States Patent [1 1 Burpee et a1.
[ INSTRUMENTED TOKEN  Inventors: Lee E. Burpee, 77 New Castle Cir.,
Goleta, Calif.; Charles D. Burpee, 4224 El Cid Way, Los Vegas, Nev.; Donald A. Paynter, 5944 Via Lemora, Goleta, Calif.
 Filed: July 13, 1972  Appl. No.: 271,456
 US. Cl. 317/262 R, 40/27.5, 194/4 F, 317/DIG. 2
 Int. Cl. G07f 1/06  Field of Search 317/D1G. 2, 262 R; 340/258 R, 258 B, 258 C, 280; 199/9 R, 9 C,
 References Cited UNITED STATES PATENTS 3,171,020 2/1965 Lord l94/4E [111 3,766,452 [45 Oct. 16, 1973 2,983,354 5/1961 Ember et a1. 40/27.5 2,774,060 12/1956 Thompson 3l7/DIG. 2
Primary ExaminerD. F. Duggan Assistant Examiner-Harry E. Moose, Jr. Attorney-John E. Wagner [5 7] ABSTRACT Disclosed is an instrumented token or chip representative of value. Concealed within or on the surface of the token is a passive resonant circuit which responds to incident electromagnetic radiation in a preselected frequency to produce and radiate a unique detectable signal indicative of the tokens presence in the inci-' dent field.
4 Claims, 9 Drawing Figures ]1 INSTRUMENTED TOKEN BACKGROUND OF THE INVENTION As soon asman developed a monetary system involving token or device of relatively light weight to be used .in exchange for goods and services, two problems emerged and have remained with us to this very day. These problems are one, that of counterfeiting by those who would skillfully make replicas of the genuine currency and the second problem is that of theft. Coins,
another currency being of the nature light in weight easily concealed, are readily subject to theft and thereafter because of their near identical shape and size are not identifiable as to source.
characteristically, these two problems are solved by independent means. Counterfeiting is minimized by ineluding in the currency certain difficult to produce features, such as precise steel die engraving or use of particular papers or materials, the supply of which is controlled. v
Automatic sensing systems have been developed for detecting counterfeit "currency which operate through the measurement of physical properties, such as weight, size, magnetic properties and the like of coins and through pattern matching in the case of paper currency.
The prevention of theft of money has been thwarted BRIEF STATEMENT OF THE INVENTION In theuse of tokens, chips and other devices, representative of money, merchandise or services, a greater degree of freedom is afforded the producer as compared with currency. This freedom may take the form of size, shape, materials, color, but when such a standard is once established, it normally must be maintained without change.
We have invented a system for both detecting counterfeit tokens or chips and segregating from valid ones, and at the same time detect the presence of genuine tokens or chips in areas where such articles are unauthorized, for example in the pocket of a departing employee.
We have invented such a system which does not change the internal characteristics of the token or chip and to all intents of purposes is identical with noninstrumented devices.
We have developed such a chipwhich is electronically'detectable and therefore may be distinguished from inert counterfeit chips. The chips in accordance with this invention are detectable remotely without physical contact. Also the chipsare passive insofar as requiringany power supply or consumable materials. This invention comprises basically a dielectric body with an inductive loop imbedded therein and terminat- BRIEF DESCRIPTION OF THE DRAWING This invention may be more clearly understood from the following detailed description and by reference to the drawing in which:
FIG. 1 is a perspective view of a chip or token in accordance with this invention;
FIG. 2 is a transverse section through the chip of FIG. 1 along the line 2-2 of FIG. 1;
FIG. 3 is a diametrical section through the chip of FIG. 1 along the line 3-3 of FIG. 1;
FIG. 3a is an enlarged fragmentary section of the view of FIG. 3;
FIG. 4 is a simplified block diagram of a system for detecting chips in accordance with this invention;
FIG. 5 is a graphical representation of the resonant characteristics of the chip of this invention;
FIG. 6 is the electrical schematic of the chip of this invention.
' FIG. 7 is a front elevational view partly in section of a tag incorporating this invention; and
FIG. 8 is a front elevational view of a currency incorporating this invention.
DETAILED DESCRIPTION OF THE INVENTION Now referring to FIG. 1, the external appearance of a token incorporating this invention may be seen. For purposes of illustration it is shown as a chip 10 of a type commonly associated with games of chance. However, the token may be of different shape and used for different purposes and may be of the type which is individually designed for the particular needs. Employing the basic concept of this invention, the token or chip may also be merely paper or cardboard with the invention actually printed thereon either visibly or imbeded in the surface to provide security. Suffice it to say the token or chip employed in this invention constitutes basically a dielectric body generally planar shape. In this case, it is shown as a circular flat disk chip l0 approximately 1 A inches in diameter and having an edge thickness in the order of lath inch. Its composition is normally that of a molded plastic either with or without inert fillers. In any case, it exhibits dielectric properties.
Given the token or chip 10 of the above dimensions, and having a weight in the order of 9 to 10 grams, the device is easily transported in the pockets, crevices of piece of paper clothing without being visible making them easily stolen. As shown in FIG. 1 the token or chip appears to be substantially identical with a chip not incorporated in this invention. Also, as will be described below the weight of the addition to the chip of this invention is substantially equal to the materials displaced so that there is virtually no detectable difference in weight from an unmodified chip.
The only change in the chip 10 is best illustrated in FIG. 2 which is a transverse section through the chip 10 of FIG. 1. It may be seen that imbedded in the periphery of the chip is a wire 11 which extends around in a loop and terminates in an element to which the ends of the wire'are electrically connected. This element is a capacitor 12 which visibly constitutes the closure of the ring and electrically constitutes the capacitance element which cooperates with the inductance of the loop wire as the loop and a capacitance of the type which has an extremely low resistance. The resonant circuit exhibits an extremely high Q in the order of 50 or more.
The minimum size and relative positioning of the resonant circuit of this invention is apparent in FIG. 3 which is a diametrical section through the chip 10. The circuit appears only as a fine wire 11 embedded in the periphery and a metallic like bar, capacitor 12, of minimum crosssection also located in the periphery of the disk or token 10. The minimum size of the resonant circuit results in minimum weight change in the chip. Through the selection of the encapsulating material 13, best seen in FIG. 3a, the weight can be compensated to avoid any change in weight from the unmodified chip.,
The edge encapsulating material 13 may be identical with that of the body of the chip and the resonant circuit actually molded in place. However, we have found that to avoid the temperatures and pressures of the molding operation that it is desireable to take a com.- pletedmolded chip, mill an edge groove, insert a wire in the groove, bond it as by soldering to the capacitance element and then seal the entire edge with a material such as epoxy resin. The resin without filler is slightly lighter weight than the normal filled disk and the weight compensation measurement is thereby achieved. v
In the completed chip it is apparent that these copper and magnetic materials are'used in the resonant circuit so'that the chip does not exhibit any ferromagnetic properties "nor 'does it emit any particles of radiation. Therefore, by simple testing with a magnet or through radiation sensitive'devices, the chip is notdetectable from normal unmodified chips. a
The parameters of the resonant circuit of this invention may be varied depending upon the size and shape of the token to be instrumented. We have found that the following components and characteristics are preferred for a conventional playing chip.
l l turn of No.18 copper wire Type, ceramic chip manufactured by U.S. Capacitor Corporation Burbank, California Capacitance: lOpfd 300 pfd wire, 11 Capacitor 12 11 and 12 as a' resonant circuit Resonant frequency: 26 I60 I MHZ The use of this invention is illustrated in FIG. 4 which is the systern shown in its simplest form. It involves a device including a signal generator 20 and a radiating antenna 21 represented simply as a box and a horn which are tuned at a preselected-frequency or narrow band of frequencies in which the resonant frequency of the chip l0,falls. lnspaced' facing relationship to the transmitter 20 is a receiving antenna 22 and a receiver 23 also tuned to the same frequency or range of frequencies. The receiver 23 initially includes a detector of the type illustrated in our copending application Ser. No. 272,831 filed July 18, 1972, which responds to ringing or sustained oscillation detected by receiver 23.
FIG. 5 represents the frequency admittance characteristics of the resonant circuit of this invention.. The
curve reflects a typical resonant peak at the selected operating frequency of the system. The narrow tall resonant peak illustrates the high Q of the circuit enhanc- Given the foregoing parameters for the resonant circuit of this invention it is possible to incorporate the same in other forms of tokens or devices. Another form of particular significance is a tag of the type commonly used in retail establishments attached to merchandise prior to sale. Such a tag 30 appears in FIG. 7. It is a multiple part tag particularly useful for inventory 'control. It includes a cord or fastening device 31 of some type or may simply be affixed to merchandise by an adhesive. The tag 30 includes one or more lines of perforations 32 dividing the tag into at least two parts, one part 33 which is removed by the sales person at the time of sale'and the remaining part 34 which remains -affixed to the article until removed'by the purchaser after arriving home. a
The tag 30 is shown in partial section illustrating that it is multilayered having an upper layer 35 upon which sales indicia is imprinted, a second layer 36 upon which the resonant circuit is deposited or printed and a third or outer layer 37 which acts as-a backing for the tag. The layers 3537 are thin so that the tag 30 exhibits no additional thickness than a conventional sales tag, Suffice it to say the layers 35-37 are of dielectric material such as paper providing a suitable body for supporting the resonant circuit made up of loop 40 and capaci-.,
tance 41 in the tag section 33.
Employing this invention, any attempt to pass the entire tag through the system of FIG. 4 will result in the detection of the presence of the resonant circuit of this The foregoing is a brief discussion of the operation of 1 the system and for more details the reference should be made to the copending applicationidentifie d above. The above described embodiments of this invention are merely descriptiveof its pi'in'ciplcs and 'are not to be considered limiting. The scope of this invention instead shall be determined from the scope of the following claims, including their equivalents.
What is claimed is:
1. An instrumented token comprisingabody of dielectric material;
passive circuit means embedded within said body;
said passive circuit means comprising at least one turn of conductive material with the ends in juxtaposed spaced end on relation with each other and constituting an inductive element;
a discrete capacitance element electrically connected to and closing the gap between the ends of said turn of conductive material;
said passive circuit means comprising a resonant circuit responsive to incident electromagnetic radiation for producing a detectable change in such electromagnetic radiation outside of said body wherein said body of dielectric m a disc with said passive circuit me the periphery thereof.
aterial comprises ans embedded in