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Light Transmissive Cards With Suppression of UV-Induced Fluorescence Disclosure Number: IPCOM000099041D
Publication Date: 2005-Mar-09
Document File: 16 page(s) / 3M

Publishing Venue

The Prior Art Database


A visible light transmissive card includes a security indicia that fluoresces under UV light. The card also includes at least one IR filter. The IR filter and/or another card layer that is substantially coextensive with a front card surface includes a component that also fluoresces under UV light. A UV blocking material is disposed between the security indicia and the UV-excitable component of the IR filter or other layer, so that the security indicia is clearly visible when the card is exposed to UV light. In some embodiments the UV blocking material is patterned to define (in combination with the fluorescing IR filter or another coextensive card layer) a secondary security indicia, which may be used in addition to or in place of the original security indicia. IR filter laminates used in the construction of such cards are also disclosed.

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Light Transmissive Cards With Suppression of UV-Induced Fluorescence


            This publication relates to cards, such as those carried for personal use.  It has particular utility for those cards that are at least in part visible light transmissive.

Recent trends in card fashions have created a demand for visible light transmissive cards (“VLT cards”), at least for financial transaction card applications.  In this regard, a “card” refers to a substantially flat, thin, stiff article that is sufficiently small for personal use.  Examples include but are not limited to financial transaction cards (including credit cards, debit cards, and smart cards), identification cards, and health cards.  A VLT card refers to a card that has at least one area through which at least a portion of visible light is transmitted, which area has an average transmission (measured with an integrating sphere to collect all light scattered in forward directions through the card) over the range from 400 to 700 nm of at least 50%, more preferably at least 70% or even 80%.  VLT cards can have a substantial amount of haze (and hence be translucent) and can be tinted or otherwise colored, such as by the incorporation of a dye or pigment, or by suitable placement of the reflection band of a multilayer optical film.  VLT cards can also be substantially transparent and colorless, e.g., water-clear.

Such VLT financial transaction cards have a curious appearance that distinguishes them from other cards, namely, that if one is held up to a light source, some light will be noticeably transmitted through the card.  Depending on the amount of haze and color of the VLT card, background objects may be visible through the card, and, if the card is placed on top of a paper or other document containing text or graphic illustrations, the text or graphic illustrations may be visible through the card.  FIG. 1 shows a VLT card 10 in perspective view.  The card has a front card surface 12, from which is visible certain embossed and/or printed information, such as a card number, name of the cardholder, and conventional printed information often including ornamental graphics.  The card is transmissive to visible light, illustrated schematically by incident visible light 14 impinging on a back side of the card being transmitted, with a somewhat diminished intensity, into transmitted visible light 14a.  The card 10 can also include other conventional features such as a signature stripe and signature, magnetic stripe, hologram(s), integrated circuit (IC) chip with or without contact pads.  To the extent any of these features are disposed on or proximate the back side of the card 10, they are generally also visible from the front side.

It has also been known for some time now to incorporate infrared (“IR”) filters in the construction of VLT cards to make them compatible with card reading machines such as Automated Teller Machines (ATMs) and the like...