CPC B42D 25/324 (2014.10) [B42D 25/29 (2014.10); B42D 25/351 (2014.10); B42D 25/355 (2014.10); B42D 25/45 (2014.10); B42D 25/455 (2014.10); B42D 25/46 (2014.10)] | 9 Claims |
1. A security document, comprising:
a substrate comprising a first surface and a second surface opposite to the first surface, the first surface comprising a cellulosic material;
an optical security device comprising:
optical indicia of authenticity of the security document, and
a third surface, the third surface comprising a thermoplastic polymer; and
an ultrasonic weld forming a bond between a section of the first surface and a section of the third surface,
wherein a first portion of the optical security device is embedded in the substrate, forming a bridge region,
wherein a second portion of the optical security device is visibly disposed on the first surface, forming a window region, and
wherein the ultrasonic weld is disposed only in the bridge region.
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