Inventors:
Peeples Jr., Walter P. (Houston, TX)
Horn, Olan F. (Houston, TX)
Greaney, John E. (Houston, TX)
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to identification cards and the like.
2. Description of the Prior Art
In the past it has been known to prepare identification cards which have photographs and fingerprints thereon to identify a particular person, and identification cards have carried magnetic identification numbers which can be read by machine. However, such cards are readily altered by changing the photograph or the fingerprints thereon or by changing the magnetic numbers.
SUMMARY OF THE INVENTION
According to the present invention a small amount of radioactive material is applied directly to a photograph or other identification indicia on the card. In a preferred embodiment of the invention the amount of radioactive material is correlated with another identification mark on the card so that the mark on the card and the amount of radioactivity can be compared to determine whether there has been a change in the radioactivity, which might indicate that the photograph or other identification indicia had been changed. Many variations and modifications of these specific embodiments shown and described herein will be apparent to those skilled in the art. Other features of the invention pointed out in the claims can best be set forth in the following detailed description of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of one preferred embodiment of the invention reference will now be made to the accompanying drawings, but the embodiments shown in the drawings are only exemplary of the invention, which can be varied by one skilled in the art.
FIG. 1 is a plan view of an identification device according to one embodiment of this invention; and
FIG. 2 is a plan view of a scintillation detector useful for detecting alterations of such devices.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 an identification card 10 is shown which is in the usual form, having a photograph 12 thereon to identify the person to whom the card is issued. The photograph has applied thereto a spot 14 of radioactive material which is substantially transparent. Preferably the entire card is laminated in a clear flexible covering such as the film sold under the trademark Mylar. This not only protects the photograph and the printing on the card but also protects the radioactive spot and prevents it from wearing off.
In this embodiment of the invention the identification card is used to identify a depositor for check cashing. The card is color coded to indicate the maximum value of check which may be cashed on this identification card. For example, one color of card is used for cashing checks up to $100.00, another color for checks up to $500.00 etc. In this embodiment of the invention the amount of radioactive material is selected to coordinate with the color code so that for every color there is a different amount of radioactivity.
When the identification card is presented for identification purposes it may be inserted into a scintillation detector or Geiger counter 16 as shown in FIG. 2, which conventionally contains means for detecting and measuring radiation and indicates the amount of radiation by means of a pointer 18 on a dial 20. A knob 22 may be used to adjust the detector for different ranges of radiation. For example, and as shown in the drawing, the detector may have five different ranges as indicated for five different positions of the knob 22, each position representing a maximum amount for which the identification card may be used for cashing checks, and each position having a color marking 24 to 32 corresponding to the color of identification card having a radioactivity within the range of the detector when the knob 22 is set at that point. The dial 20 may be divided into a "good" area and higher and lower "unacceptable" areas 34 and 36. Alternatively, the dial may have five segments, one for each card color and radiation amount, and the detector may operate on only a single range.
A particular identification card 10 may, for example, be intended to be used for cashing checks in value up to $1,000.00. Such a card will have applied to it at 14 sufficient radioactive material to cause the pointer 18 to point to the "good" area of the dial when the knob 22 is turned to point at color spot 28. When a term such as "sufficient radioactive material" or "selected amount of radioactive material" is used, this is intended to relate to a given amount of radioactive emission stemming from the material. This would include, therefore, varying the particular material, as well as the quantity of material. Color spot 28, in the example shown, is silver in color, which is the same color as the card. If the identification indicia has been altered in such a way as to change the radiation of the radioactive material, the detector would indicate less or more radiation and the pointer 18 would point to one of the unacceptable areas 34 and 36, thereby revealing the alteration of the card.
It is apparent that when the radiation spot is applied directly upon the photograph, any attempt to remove the photograph will remove most of the radioactive material. Furthermore, an attempt to place a photograph over the original photograph will cause shielding of the radioactive material, thereby reducing the emission of the material and changing the reading of the scintillation detector.
It is apparent that identification indicia other than a photograph can be used. For example, fingerprints, numbers, or signatures can be used to identify holders of the cards. Furthermore, it is apparent that group indicia other than colors can be used to identify specific groups of cards. For example, the groups may be identified by letter, number, symbol, shape or size. Preferably the cards, and thereby the radioactive material thereon, are protected by laminating in a clear flexible material such as the material sold under the trademark Mylar.
The radioactive material used should be one having a half life of a substantial period so that the radioactivity will not be reduced by any substantial amount during the period during which the card is to be used. Furthermore, it is desirable that the material used have a mild gamma energy emission because of the safety factors involved. For economic reasons the material used should be of low cost. The isotope which most nearly fits these requirements is cesium-137, and this is the preferred isotope. Other isotopes which may be used include radium 226 and americium-241.
To avoid the possibility of injury to persons who carry the identification devices of this invention, the quantity of isotope used is necessarily very small. Thus the maximum amount is less than one micro curie. If an isotope such as cesium-137 is used it may be used in the form of cesium chloride, which is a powder which can be readily dispersed in a liquid acrylic or other transparent plastic material and dropped onto the photograph where it will spread out and harden into a transparent and adherent cover on the photograph.
Various embodiments of the invention are shown in the drawing and described in the specification, but many variations thereof will be apparent to those skilled in the art. It is not practical to show or describe all the variations included within the invention, and therefore the embodiments described should be considered illustrative only, and not limiting, the scope of the invention being as broad as is defined by the appended claims. The form of the claims and the specification, including the Abstract, is adopted solely for easier reading and understanding, and should not be considered in interpreting the scope of the invention claimed.