US 3802101 A
A coded identification card which includes a core sheet and an outer adherent covering for the core sheet. The core sheet has a given transmissivity to radiant energy of a given frequency and intensity or a given range of frequencies and intensities while preselected coded regions of the core sheet have a transmissivity which differs from that of the remainder of the core sheet. The outer adherent covering for the core sheet has a higher transmissivity to the radiant energy than the lowest transmissivity portion of the core sheet. The outer adherent covering preferably has a transmissivity which obscures the preselected coded regions from view by the naked eye.
Description (Le texte OCR peut contenir des erreurs.)
United States Patent 1 Sc antlin I CODED IDENTIFICATION CARD  Inventor: John R. Scantlin, Los Angeles,
211 ApplL No.: 223,272
[52 U.S. c1. 40/22  Int. Cl. G09f 3/02  Field of Search 40/22, 135, 133; 283/6, 283/7  v 7 References Cited 1 UNlTED STATES PATENTS 2,395,804 3/1946 ,DeGruchy 283/7 x 2,835,993 5/1958 Whitehead. 40/22 2,984.030 5/1961 Hannon 40/22 3,160,155 12/1964 Bragg et'aL. 283/7 X 3,195,257 7/l965 Weihe 40/158 R 3,245,697 4/1966 Nugent 283/7 9/1969 Makishima 283/6 X [111 9 3,802,101 I451 Apr. 9, 1974 1'0/1970 Travioli 235/61.6R
3,566,521 3/1971 Conner 40/2.2 3,643,358 2/1972 Morderosian 40/22 Primary Examiner-Joseph S. Reich Assistant Examiner-Wenceslao J. Contreras Attorney, Agent, or Firm- Smyth, Roston & Pavitt [5 7] ABSTRACT A coded identification card which includes a core core sheet. The outeradherentcovering preferably has a transmissivitywhich obscures the preselected coded regions from view by the naked eye.
. 6 Claims, 12 Drawing Figures PATENTEDAPR 9 I974 sugar 1 0F 3 OO O OO O O OO O 0 OOO RATENTEBAPR 9 i974 SHEET 3 BF 3 O OO O O OO O 0 OOO ' m Ill" I 1 CODED IDENTIFICATION CARD- BACKGROUND OF THE INVENTION Within recent years, there has been a tremendous increase in the use of credit cards by the purchasing public. Indeed, the use of credit cards has become so wide spread that the retailer who demands cash operates at a considerable disadvantage with respect to his competitor who will honor a credit card.
Due to competitive pressures, credit cards have been issued by all manner of businesses such as petroleum companies, air lines, department stores, etc. The net result has been a proliferation of credit cards such that a businessman or housewife may not feel properly attired unless accompanied by a bulging wallet or purse containing 20 or more credit cards.
As a convenience to purchasers and also to small businesses which do not have the sales'volume to justify issuance of their own credit cards, there has evolved the multi-purpose credit card. The holder of sucha other advantages for the consumer. The major multipurpose credit cards are generally recognized over large geographical areas so that apurchaser, for example, living in California might charge purchases while on vacation in Europe tohis credit card. Such flexibility was not generally possible with the limited-purpose credit cards which were frequently issued by a mediumsized business for usage within a confined geographical area..As a furtheradvantage of rnulti-purpose credit cards, the credit card may be issued, for example, bya bank and be keyed to the holders account at the bank. With this type of arrangement, the purchases made by the card holder may be debited against his checking account with the bank. With this innovation, it is now not even necessary forthe credit card holder to make out a check for his monthly statement since the handled automatically by his bank.
A disadvantage in the increasing usage of multipurpose credit cards by the public has been a corresponding increase in the losses by business due to use of fraudulently acquired or stolen credit cards. Whereas a thief using a limited-purpose credit card might conceivably run up charges of several hundred dollars in a short period of time, the loss exposure resulting from fraudulent use of a multi-purpose credit card can be many thousands of dollars. As a corollary problem, the use of a multi-purpose credit card is much more difficult to police than that of a limited-purpose credit card. For example, if a limited-purpose credit card is stolen, the notification of the theft need only be communipaymfent is cated to personnel of the issuing business, which might the credit card holder who might protect himself by carrying insurance to cover such losses. Recently, however, legislation has been enacted which sharply'reduces the ability of the issuer of the multi-purpose credit card to pass on the risk of loss to the credit card owner. Thus, this has made it imperative that a multipurpose credit card be devised which is substantially fraud proof and whose usage may be readily policed by the credit card user.
At present, there is under consideration the use of multi-purpose credit cards whose usagewill be keyed to a central computer, Individual businesses which honor a particular credit card will have a readout device on the premises which will be keyed to the central computer. Before honoring the creditcard, it will be inserted into the readout device which will then transmit the information on the credit card to the computer. Within a relatively short period, the computer will then either authorize the useof the credit card or inform. the businessman that this particular credit .card has been reported stolen and should not be honored.
Further, the use of such a computerized system may provide information as to the purchasing limits permitted with the particular credit card or whether the credit the computer may contain information on the purchas- .ing pattern of the credit cardholder which would indicate a purchase whose amount was completely inconsistent with the previous purchasing pattern. Given such a computerized system, the use of multi-purpose credit cards will be much more effectively policed to reduce losses from their fraudulent use.
In devising a multi-purpose credit cardfor use in a computerized system, it is imperative that the credit card besubstant'iallyfraud proof so that it may not be altered byan ingenious thief to provide false information for the computer. One means which has been suggested is to merely punch holes in the credit card with the arrangement of holes providing a readout code for a computer. Such a credit card would not be satisfactory for several reasons. First, the holes in the credit card could collect dirt or other debris which. would interfere with the readout of the information on the credit card. Second, the hole pattern could be easily altered by an ingenious thief to provide false information for the computer.
A second form of construction which has been suggested, and which. may soon be widely adopted, is to place a strip of magnetic material on the surface of the credit card. The orientation of the magnetic particles in the strip would contain coded. information which could be read and transmitted to a central computer.
This type of credit card construction is' also unsatisfactory since the coded information may also be altered by an ingenious thief to'provide false information for the computer. By passing the magnetic strip beneath a magnetic head, for example, themagnetic strip could be erased with new and false information then being placed on the strip to confuse the computer.
A still further form of construction which has been suggested is toplace bits of magnetic material at preselected locations within the credit. card. This type of card is also not satisfactory because it is'difficult to construct and difficult to read due to the presence of an overlying layer of plastic material.
At the present time, there is a very substantial need for a credit card which can be easily read and contains coded information which cannot be altered, even by the most ingenious of thieves, to provide false information for the computer. The continuing battle of the U. S. Department of the Treasury with counterfeiters demonstrates the ingenuity and persistence possessed by individuals intent on crime. It may be reasonably anticipated that the same degree of persistence and ingenuity will be exercised by persons intent on credit card fraud. Thus, the problem of providing an easily read, yet fraud-proof credit card, is a very real one which demands a solution to provide the basis for a workable computerized system regulating the use of multipurpose credit cards.
SUMMARY OF THE INVENTION The present invention provides a solution to the problem of a fraud-proof credit card by providing a card which contains coded information that 'may be read by passing radiant energy through the card. The card includes acore sheet of a material which has a given transmissivity to radiant energy of a given frequency and intensity. Included in the core sheet are preselected coded regions whose transmissivity differs from that of the remainder of the core sheet. An outer adherent covering is provided for the core sheet which has a higher transmissivity to the radiant energy than those portions of the core sheet having the lowest transmissivity to the radiant energy, i.e., either the preselected coded regions or the remainder of the core sheet. I v
The-coded regions in the core sheet may either have a higher or a lower transmissivity toradiant energy of a given frequency and intensity than the remainder of the core sheet. Conveniently, the preselected coded regions may take the form of holes which are punched in the core sheet. Thus, when the coded identification card is exposed to the radiant energy, the energy passes through the. outer adherent covering, and through the holes in the core sheet but does not pass through the core sheet itself. The energy passing through the core sheet may then be received by sensors which translate the presence or absence of radiant energy into data bits which are fed to a computer.
The coded information on the identification card, as described above, is contained within the core of the card, which, issurrounded by an adherent covering. Thus, the encoded regions on the core sheet are protected from dirt, debris, or tampering by the outer adherent covering. To alter this coded information, it would be necessary to first remove the outer adherent covering. This would destroy the card andmake it completely unusable in an attempt to provide falseinformation for the'computer... Preferably, the coded identification card has an cute covering whose transmissivity obscures the preselected coded regions-from view by the naked eye. The coded.
laminated to 'outer sheets of a plastic material are adhered to the core sheet.
The inner-core sheet is composed of a material having a given transmissivity to radiant energy of a given frequency and intensity or range 'of frequencies and intensities and the core sheet has preselected coded regions whose transmissivity differs from that of the remainder of the sheet. The outer sheets have a transmissivity to the radiant energy which is higher than the lowest transmissivity portion of the core sheet; If, for example, the preselected coded regions have a lower transmissivity than the remainder of the core sheet, the outer sheets would have a higher transmissivity to the radiant energy than the coded regions, but not necessarily higher than the transmissivity of the remainder of the core sheet. on the other hand, if the preselected coded regions have a transmissivity which is higher than that of the remainder of the core sheet, the outer sheets have a transmissivity which is higher than the transmissivity of the remainder of the core sheet, but not necessarily higher than the transmissivity of the coded regions.
In a preferred form of the coded identification card, the outer sheets are preferably composed of a plastic material and are laminated to the inner-core sheet. The core sheet may likewise be formed of a plastic material or of a thin sheet of metal or a sheet of metal clad with a plastic material. The coded regions on the inner-core sheet may be formed by punching a preselected hole pattern in the core sheet,by a photographic process in which preselected high or low transmissivity areas are imposed on the core sheet, or by any means which provides the preselected coded regions with a transmissivity to radiant energy which differs from that of the remainder of the core sheet. As stated previously, the outer sheets which are adhered to the inner-core sheet preferably have a transmissivity which obscures the preselected coded regions from view by the naked eye. Thus, the credit card holder is probably not aware of the coded information contained within the interior of the identification card. Moreover, the construction of the card makes it difficult to observe and impossible to change the preselected coded'information without first physically removing the cover sheets from the inner core sheet. This wouldresult in the destruction of the card and make it unusable. Moreover, in removing the outer sheets, the core sheet might well be obliterated so that it would then not be possible to observe the coded pattern previously contained on the core sheet.
which BRIEF DESCRIPTION OF THE DRAWINGS struction showing the appearance of the coded holes in cross section; i
FIG. 4 is a plan view along the-lines 4-4 of FIG. 3 of a core sheet as employed in my card construction in which the coded information is presented in the form of holes in a coded pattern;
FIG. 5 is a plan veiw of a core embodiment of my card construction in which the coded information is in the form of preselected low-transmissivity areas on the core surfacej FIG. 6 is a sectional veiw of a further form of core construction in which the core is formed of a metallic sheet having sheets of a plastic material adhered thereto; l
FIG. 7is a sectional view of the core element of FIG. 6 illustrating the flow of plastic material into the holes within the metallic sheetdue to the effect of heat and pressure applied to the plastic covering material;
7 FIG. 8 is an enlarged sectional view of the core element of FIG. 7;
FIG. 9 is an enlarged sectional view of a metallic core element which isbonded to sheets of a plastic material through use of a thermosetting glue;
FIG. .10 is a plan view of a further embodiment of a metallic core element in which holes are provided adjacent the corners of the element to improve the adherence of the overlying plastic sheets to the core element;
FIG. 11 is a plan view of a further embodiment of the identification card in which the core is formed of a metallic'sheet' having sheets of plastic material adhered interior of the card are preselected coded'areas in the form of holes 6, whose transmissivity differs from that of the sheet of core material aswi ll be described. Preferably, the preselected coded regions, or holes 6, are obscured from view by the naked eye due to the cards construction arid, thus, are shown, in phantom line drawingin FIG. 1. I I
' The card, as shown in FIG. 2, may be of a laminated construction in which a core sheet 8 has cover sheets 10 and 12 adhered thereto, which are in turn covered by outer sheets 14 and 16. The core sheet 8,.as shown in FIG. 4, has a giventransmissivity to radiant energy of a preselected wave length and intensity. Thepr'eselected coded regions ofthe core sheet 8, shown as holes 6 in FIG. 4, have a higher transmissivity to the radiant energy than does the remainder of the core sheet. Thus, i
as the radiant energy impinges upon the core sheet 8,
it passes through the holes 6 to convey coded inforrna tion but does not pass'through the core sheet 8.
The cover sheets 10 ,and 12, shown in FIG. 2, have a transmissivity which is higher than the portions of the coresheet 8 having the lowest transmissivity. Thus, when the coded information contained in the core sheet 8 is in the form of punched holes 6, the transmissivity of the cover sheets 10 and 12 will be higher than the transmissivity of the core sheet itself, but not necessarily higher than the transmissivity of the coded regions. Preferably, the transmissivity of the cover sheets wand 12 is sufficiently low to obscure the coded regions in the core sheet 8 from view'by the naked eye. For example, the cover sheets 10 and 12 may be coded regions formed of white polyvinyl chloride, and the core sheet 8 may be formed of black polyvinyl chloride. Also, the cover sheets 10 and 12 may conveniently be supplied with a matte finish which is suitable for printing. The printed information or indicia, as illustrated at 4, may be printed on the cover sheets 10 or 12 prior to their being laminated or adhered to the core sheet 8 to form a a finished card.
As shown in the construction illustrated in FIG. 2, the outer sheets 14 and 16 overlie the cover sheets 10 and 12. These outer sheets give the card a shiny. outer surface and provide convenient surfaces for subsequently embossing the card (not shown) with the holders name or address, etc.
. In the layered construction of the card illustrated in FIG. 2, the various layers may be adhered together in any suitable manner to form a finished credit card. Thus, the various layers may be adhered together with a glue or, if they various layers are formed of compatible materials which adhere together under the effects of heat and pressure, they may be laminated or pressed to form the finished card. The thickness of the various layers may be varied depending upon the desired thickness of the finished card, its strength, etc.
In a more simplified embodiment of the invention, as
shown inFIG. 3, the card maybe of a three-layered construction in which the core sheet 8 has cover sheets- 10 and 12 adhered thereto. The coded information within the core sheet 8 is illustrated in the form of holes 6 in the core-sheet8 having preselected locations. Ac-
tually, the number of layersemployed in the card, if of bris and tampering by overlyingsheets positioned outwardly of r the core sheet which preferably obscure the of the core sheet from view by the naked eye.
Also, in utilizing the invention, several core sheets may be employed within a single card with each of thecore sheets having codedinforrnaation hereon in the form of preselected regions whose transmissiv-ity to radiant energy differs from'that of the remainder of the particular core sheet. In acard containing several core sheets, one of the core sheets'may, for example, have a selectively low transmissivity to radiant energy of a given frequency and'intensity while another of the core sheets mayhave a selectively lowtransmissivity to radiant energy of a different frequency and intensity. In the use of such a card, the card may be exposed to one source of radiant energy which passes through one of the core sheets but onlythrough preselected coded regions of a second core sheet to reveal coded information on the second core. sheet. Following'this, the card may thenbe exposed to a different source of radiant energy which passes through only the preselected coded regions of thefirst core'sheet but completely through the second core sheetto reveal only the coded information on the first core sheet.
Turning to FIG. 5, in a further embodiment of the invention, a core sheet 8a may contain coded infonnation in the form of dots 18 or other indicia arranged on the core sheet to form a coded pattern. The dots 18 have a lower transmissivity than the remainder of the core sheet 8a. Thus, when radiantenergy is caused to impinge upon core sheet 80, after passing through a covering which is adherently bonded to the core sheet, the radiant energy will pass through the core sheet but not through the low-transmissivity areas 18. Using this construction, the reading device may then sense the absenceof radiant energy at the low-transmissivity areas 18 to determine the coded information.
In a further embodiment of the invention, as shown in FIG. 6, a core sheet 20 may be employed which is composed of a thin metallic inner sheet 22 having coating sheets 24 and 26 adherently bonded thereto. Typically, for example, the inner sheet 22 may be formed of aluminum and the coating sheets 24 and 26 may be formed of polyvinyl'chloride. Such composite structures are commercially available and are used in wrapping materials of various types such as wrappings for food products.
The core 20 may contain preselected coded regions having a higher-transmissivity to radiant energy in the form of holes 25 punched in a predetermined manner. The use of the core sheet 20 is quite advantageous in forming'a laminated card structurewhich is formed by i the use of heat and pressure. During the laminating procedure, there may be some tendency to run or undergo plastic deformation. In some instances, depending on the conditions employed, this may result in deformation of the pattern of previously encoded information on the core material. If, for example, the information encoded on the core sheet is in the form of holes, the holes may be deformed by the lamination procedure such that the information cannot be properly read by the card view-erwhen thecard is exposed to radiant energy. The composite core sheet 20, shown in FIG.- 6, provides structural integrity for the coded hole pattern, even though the coating sheets 24 and 26m'ay'be deformed by the laminating procedure.
,As illustrated in FIG. 7, with respect to a laminated card 27,'the holes 25 which previously passed through the entire core 20, as shown in FIG. 6, have partially closed due to the plastic flow of the material in the cover sheets wand 12 and the coating sheets 24 and 26 due to the effect of heat and pressure with plastic 28 forced into the holes 25. However, due to the structural integrityof the 'metal sheet 22, the plastic flow of the The plastic flow of material into the holes 25 pro-- vides an identification card having greater strength by providing better bonding between the metal sheet 22, the overlying plastic layers 24 and 26 and the cover sheets 10 and I2. In the core construction illustrated in FIGS. 6-8, it should, ofcourse, be understood that the transmissivity of the cover sheets 10 and' I2 and the coating sheets 24 and 2.6 is such that the flow of plastic material 28 into the holes 25 does not reduce the transmissivity of the holes below whatever value is required in the performance of the card.
Turning to FIG. 9, there is shown a further embodiment of an identification card 29 in which a metallic core sheet 22a is directly bonded to cover sheets 10 and 12 to form the completed card. A thennosetting glue may be employed in bonding the metallic sheet 22a to the cover sheets 10 and 12 and a coating of glue may be applied to the surfaces of the metallic sheet 22a prior to its bonding to the cover sheets. Thermosetting glues of this type are also available in the form of thin sheets which may be merely laid between the sheets to be bonded together. Then, under the effects of heat and pressure, the sheet of thermoplastic glue may be melted and permanently set to form a bond between the metallic coresheet 22a and the cover sheets 10 and 12.
As illustrated in FIG. 9, coded information in the form of punched holes 32 is contained in the core sheet 22a. These holes pass only through the metallic core sheet 22a,.as opposed to holes 25 which pass through a core sheet 22 and also through coating sheets 24 and 26 when the core sheet is clad with a plastic as in FIG. 6. Since the core sheet 22a is not clad with coating sheets, the volume of the holes 32 is less than the volume of the holes 25 which pass through both the core sheet and the cladding. It may be advantageous in some cases to reduce the volume of holes in the metallic core sheet whose location conveys coded information. One way of accomplishing this is to reduce the thickness of the core sheet which has been done in the. embodiment of FIG. 9 by eliminating the coating sheetsor the cladding for the core sheet. By reducing the thickness of the core sheet and the volume of the holes therein there is less free volume within-the core sheet. Thus, when the metallic core sheet is bonded to overlying plastic sheets through the use of heat and pressure, there will be less a free volumeto accommodate the flow of plastic material into holes within the core sheet. There will be some flow of plastic material into the core sheet 22a, as illustrated at 34; however, since this flow is reduced by the reduced free volume of the holes, .there will be lesstendency for the formation of dimples. or minute depressions in the outer surface" of the cover sheets wand 12.
' able. Thus, to the extend that the formation of dimples or slight depressions in the outer surfaces of the plastic sheets may be a problem with a particular card construction, the problem can be lessened by employing the card construction illustrated in FIG. 9.
In the bonding of overlying plastiesheets to a metallic core sheet in the formation of a coded identification card, there may, in some instances, be a tendency for delamination to take place at the interface between the plastic and metal. To the extent that this is a problem in a particular card construction, a modification of the core sheet 22b, may be utilized, as illustrated in FIG. 10. The coresheet 22b may contain coded information in the form-of punched holes 36 and, in addition, contains punched holes 30 located adjacent the corners of the core sheet. When the core sheet 22b is then laminated to overlying plastic sheets in the formation of a coded identification card, the effects of heat'and pressure will cause plastic to flow into the punched holes 30. This will result in strengthening'the bond between the core sheet 22b and the overlying plastic sheets in the regions adjacent the comers of the identification card. If delamination occurs, it will generally begin at one of the corners since the corners are the points of greatest weakness. By providing holes 30 through the core sheet 22b in the region of its corners, any tendency for delamination to take place at the corners is lessened.
As illustrated in FIG. 10, the holes 30 are of the same size as the holes 36. If desired, however, the holes 30 may be made substantially larger than the holes 36 to provide increased freevolume within the metallic core sheet 22b at its corners to accommodate the flow of plastic during lamination. Since the locations of the holes 30 donot convey coded information, the formation of dimples or depressions in the outer surfaces of the overlying plastic sheets at the corners is not objcctionable;
. .In a further embodiment of the invention, as illustrated in FIG. 11, an identification card 37 is provided which contains a me'talliccore sheet 226 having ,a dimension smaller than that of the identification card. As illustrated, the metallic core'sheet 22c containscoded information in the form of punched holes 38.
FIG; 12, which is a sectional view along the line 12-12 of FIG. 11., illustrates plastic cover sheets 10 and 12 overlying the metallic core sheet 220 and adherently bonded theretoOuter sheets 14 and 16 may, in turn, be adherently bonded to the cover sheets 10 and 12 to produce a fivedayered card construction. Since the core sheet 220 is of a smaller dimension than the identification card 37, the cover sheets 10 and 12 are adherently bonded to each other about the periphery ofthe card. This provides a stronger bond about the periphery of the card which serves to prevent delamination. As illustrated, the plastic material in cover sheets 10 and 12 flows, under the effects of heat and pressure, in the regions adjacent to the edges 40 of the core sheet 22a to substantially fill these regions with plastic.
A five-layeredcard construction is illustrated in FIGS. 11 and 12. If desired, however, a three-layered construction could'b'e formed byeliminating the outer sheets 14 and 16. Depending on the heat and pressure used in lamination and the thickness of the plastic sheets, there may be some tendency for the identification card 37 tobe thinner adjacent its edgesQI-Iow ever, this is not objectionable since a difference in the thickness of the card adjacent its edges will not detract from its usefulness.
In the coded patterns illustrated in the various views of the drawings, the holes are arranged in a binary configuration reading from the top toward the bottom of the card. As illustrated, a four-hole pattern can be employed for each number on thecard in which a hole punched in the first or topmost location would indicate the number I; in the next location reading down the card, the number 2; in the next location reading down the card, the number 4, and in the last or bottom location reading down the card, the number 8. This is merely one way of encoding information on the core sheet and is used only for purposesof illustration. It should be understood that any pattern may be utilized for encoding the information on the core sheet and that the invention is not concerned with any particular sys temof encoding.
The source of radiant energy employed in reading the coded information on the identification card of the present invention will generally emit energy covering a riphery of said card.
range of frequencies and intensities. Also, however, a source of coherent radiant energy, such as a laser beam, may be employed. Theterminology given frequency and intensity, as used herein in referring to transmissivity, does not, therefore, indicate the'use of a source of coherent radiant energyin reading the information on the card.
It should be understood that printing or other indicia may be positioned in overlying relation with respect to the encoded regions of the core sheet of the card. This will not adversely affect the functioning of the card providing that the printing does not change the transmissivity of the covering layer or layers for the core sheet so as to prevent the sensing of radiant energy or the absence of radiant energy at the locations of the preselected coded regions.
I claim: I
1. A codedidentification card comprising:
a metallic core sheet having a given transmissivity to radiant energy of a given frequency and intensity;
said core sheet having pre-selected coded regions in saidouter sheetsbeing laminated to said core sheet,"
and said plastic cladding on said core sheet and the plastic of said outer sheets extending into said openings as a result of heat and pressure employed in laminating said outer sheets to said core sheet, whereby the bond between said core sheet and said outer sheets is enhanced to provide a stronger identification card.
2. The coded identification card of claim 1 wherein said core sheetis of a smaller dimension than said card, and said outer sheets extend 'beyond the peripheral edges of the core sheet with the outer sheets being bonded to each other in the regionradjacent to the pe 3. The coded identification card of claim 1 wherein said core sheet and said card are of a rectangular configuration with said core sheet having openings therein adjacent its corners and the corners of said card, and
the plastic from said outer sheets extending into the openings adjacent the corners of the core sheet to strengthen the plastic-to-metal bond in the region of said corners. V 4. The identification card of claim 1 wherein said outer sheets have a transmissivity which obscures said pre-selected coded regions from view by the naked eye.
5. The identification card of claim 2 wherein said outer sheets have a transmissivity which obscures said preselected coded regions from view by the naked eye. t
6. The identification card of claim 3 wherein said outer sheets have a transmissivity which obscures said pre-selected coded regions from view by the naked eye.
Citations de brevets