CREDIT CARD

• US 3,873,813 A
• Filed: 05/18/1973
• Issued: 03/25/1975
• Est. Priority Date: 05/18/1973
• Status: Expired due to Term

• Current Assignee: James M. Wilson, Roy J. Lahr
• Original Assignee: James M. Wilson, Roy J. Lahr
• Inventors: Lahr, Roy J., Wilson, James M.
• Primary Examiner(s): Urynowicz, Jr., Stanley M.
• Application Number:
  US05/361,741
• Time in Patent Office: 676 Days
• Field of Search: 235/61.12N,61.11E,61.7B,61.8R,61.8A 340/173CC,173LT 356/71 250/209,226 194/4R
• US Class Current: 235/380
• CPC Class Codes: G06K 19/14 the marking being sensed by radiation
• CPC Class Codes: G06Q 20/3433 the counter having monetary units
• CPC Class Codes: G07F 7/02 by keys or other credit registering devices
• CPC Class Codes: G07F 7/086 by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: Y10S 283/904 Credit card

Abstract

A credit card having a coating of a substance which when treated sufficiently permanently and irreversably changes from a first state having one characteristic of reflectivity for visible light components incident thereon to a second state having a second characteristic of reflectivity for the light components. Preferably, in the first state the substance is highly light reflective, and reflects light of different wavelengths unequally, and in the second state the substance is light transparent. Treating of the substance is accomplished by heating the substance, preferably with a high intensity light beam. Authenticity of the credit card is achieved by first measuring the amplitude of visible light components (colors) reflected by the substance when the substance is treated intitially, and by a later spectral reflectance test after additional treating which, by sensing the change in amplitude of a previously highly reflected visible light component, indicates that the substance has changed to the second state in response to the additional treating. The coating is deposited on a layer of a highly light absorptive material which enhances the reflectance contrast between the first and second states of the coating and promotes rapid treating of the coating.

Claims

1. A credit card comprising a support layer, and a coating of heat-sensitive substance supported by said layer, said heat-sensitive subtance being responsive to energy from a remote source incident upon said substance and having a first optical reflectance characteristic when within a first temperature range, and a second, different optical reflectance characteristic when heated to a temperature beyond said first temperature range, said second optical reflectance characteristic of said substance being permanent even when exposed to said energy from said remote source once said substance is heated beyond said first temperature range.

2. The credit card of claim 1 in which said heat-sensitive substance comprises a material which is light reflective when within said first temperature range, and which is light transparent when heated to a temperature beyond said first temperature range.

3. The credit card of claim 1 wherein said heat-sensitive substance comprises a material which is highly reflective of light of a given frequency when within said first temperature range, and which is not highly reflective of light of said given frequency when heated beyond said first temperature range.

4. The credit card of claim 3 wherein a sheet of a highly light absorptive material is positioned between said support layer and said coating of said heat-senstive substance on said support.

5. The credit card of claim 4 said light of said given frequency is blue and said sheet of highly light absorptive material is black.

6. The credit card of claim 2 wherein said material reflects a large amount of blue light, a lesser amount of red light, and a still lesser amount of green light when within said first temperature range.

7. A credit card comprising a support layer, a coating of a heat-sensitive substance supported by said layer, said heat-sensitive substance being reponsive to energy from an external source incident upon said substance and having a first range of light reflectance when within a first temperature range, and a second, different range of light reflectance when heated to a temperature beyond said first temperature range, the second range of light reflectance of said substance being permanent even when exposed to energy from said external source once said substance is heated beyond said first temperature range, and means positioned between said support layer and said coating of a heat-sensitive substance for enhancing the optical contrast between said first and second optical reflectance characteristics of said heat-sensitive substance.

8. The credit card of claim 7 in which said heat-sensitive substance comprises a material which is highly reflective when within said first temperature range, and which is highly light transparent when heated to a temperature beyond said first temperature range.

9. The credit card of claim 7 in which said heat-sensitive substance comprises material which is highly reflective of light of a given frequency when within said first range, and which is highly transparent to said light of said given frequency when heated to a temperture beyond said second range.

10. A credit card comprising a transparent support layer a sheet of a highly light absorptive substance deposited on said support layer, and a coating of a heat-alterable material on said highly absorptive material, said heat-alterable material being highly reflective of light of at least one color when within a first range of temperatures and transparent to said light of said one color when heated to a temperature beyond said first range of temperatures.

11. A method of testing the authenticity of a credit card having a coating of a heat-sensitive substance having a first optical reflectance characteristic when within a first temperature range and a second optical reflectance characteristic when heated to a temperature beyond said first temperature range, comprising the steps of:

measuring the magnitude of light of at least one color reflected by said substance when said substance is within said first temperature range to produce a first signal representative of the amplitude of said one color, heating said substance to a temperature beyond said first temperature range, measuring the magnitude of said light of said one color reflected by said substance when said substance is heated beyond first temperature range to produce a second signal representative of the amplitude of said one color, and using both said signals to determine the authenticity of said credit card.

12. The method of claim 11 wherein heating of said substance is achieved by a high intensity light beam, said beam also being used in making both said measurements.

13. The method of claim 11 wherein said signals representative of the amplitude of said light of said one color are electricaly integrated.

14. A method of testing the authenticity of a credit card having a coating of a heat-sensitive substance which is light reflective when within a first range of temperatures and light transparent when heated to a temperature beyond said first temperature range, comprising the steps of producing signals representative of the amplitudes of light of at least two different colors reflected by said substance when said substance is within said first temperature range, and when said substance is heated to a temperature beyond said first temperature range, electrically integrating each of said signals to derive signals that have a time-amplitude characteristic determined by the amplitude of each of said signals, and supplying said signals having said time-amplitude relationship characteristic to a logic circuit when said substance is both within said firSt temperature range and heated to a temperature beyond said first temperature range.