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PERSONALIZED POLYCARBONATE SECURITY FEATURE FOR IDENTITY DOCUMENTS

IP.com Disclosure Number: IPCOM000235475D
Publication Date: 2014-Mar-03
Document File: 23 page(s) / 1M

Publishing Venue

The IP.com Prior Art Database

Abstract

The present publication relates to a polycarbonate (PC) security feature comprising two or more azimuthal planes of personalized and/or non-personalized obliquely angled images which are laser engraved into a PC Laser-Engraveable (LE) layer via a radially symmetric, two-dimensional (2D) spherical or aspheric microlens array patch. The process described herein is an enhancement of the customary Multiple Laser Image (MLI) and Changeable Laser Image (CLI) processes prevalent in PC cards and PC passport biodatapages, which only allow for one plane of images to be written, via a one-dimensional (1D) lenticular lens array. The present disclosure uses what is commonly called Fly’s Eye Array (FEA) and places no limit to the number of angularly separated but spatially overlapping images other than the viewing quality degradation due to ghosting for a large number of multiplexed images. In a preferred embodiment, two planes of laser images along two principal orthogonal axes are alternatively switched to the viewing zone by tilting the PC security document to align to the original writing beam direction.

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PERSONALIZED POLYCARBONATE SECURITY FEATURE FOR IDENTITY DOCUMENTS

Abstract

    The present publication relates to a polycarbonate (PC) security feature comprising two or more azimuthal planes of personalized and/or non-personalized obliquely angled images which are laser engraved into a PC Laser-Engraveable (LE) layer via a radially symmetric, two- dimensional (2D) spherical or aspheric microlens array patch. The process described herein is an enhancement of the customary Multiple Laser Image (MLI) and Changeable Laser Image (CLI) processes prevalent in PC cards and PC passport biodatapages, which only allow for one plane of images to be written, via a one-dimensional (1D) lenticular lens array. The present disclosure uses what is commonly called Fly's Eye Array (FEA) and places no limit to the number of angularly separated but spatially overlapping images other than the viewing quality degradation due to ghosting for a large number of multiplexed images. In a preferred embodiment, two planes of laser images along two principal orthogonal axes are alternatively switched to the viewing zone by tilting the PC security document to align to the original writing beam direction.

Background

    Polycarbonate (PC) security documents, including National Identification (NID) cards, Driver Licenses (DL) and passport biodatapages (BDP) offer the highest security owing to the indelible personalization marking of the Laser Engraver (LE) layer in the PC card stack. The PC security document comprises between seven (7) to 12 layers. Typically, the outer layers are clear, protecting the LE layers underneath and LE layer bounding the center white core layers which are typically used for security printing. All the PC layers are fused together at a high temperature, typically 175 degrees Celsius or higher via a film lamination process without using any liquid or solid adhesives. Once fused, the stack of films becomes a block of solid PC material. As a result, these PC security documents are very durable and are often rated for ten years of life under normal use. A typical PC security document construction is illustrated in Figure 1. The white core layer can optionally include a chip inlay to allow for contact and/or contactless access to electronic data storage.


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Figure 1: A typical construction of PC security document stack.

    In a typical setup, a 1064 infra-red laser is directed through the top clear layer and made to interact with the carbon rich LE layer underneath. The localized absorption causes charring of the PC grains in dependence with the personalization data, such as the card holder's photograph and/or demographic data. Only monochrome gray-scale engraving is supported by traditional laser engraving process. Laser engraved personal data is permanent and cannot be reversed or removed. As an added bonus, the personalization is effected in the inner LE layer and not on the surface of the security document. Both of these PC laser person...