Patent · US Active

Card-shaped data carrier

US8778834B2 · kind B2 · utility

1Cited by

3References

13Claims

0Family size

Assignee

GIESECKE & DEVRIENT GMBH · DE

Inventors

Günter Endres · Birkenfeld, DE
Tobias Salzer · Unterhaching, DE

Key dates

Filing date	Nov 9, 2010
Grant date	Jul 15, 2014
Priority date	—
Expiry date	Jan 23, 2031

Classification

Technology area (CPC G)Physics
CPC primaryG02B5/23
WIPO fieldOther consumer goods
WIPO sectorOther fields

Abstract

A multi-layer card-shaped data carrier has a marking layer containing a hidden marking, and a thermochromic cover layer arranged over the marking layer at least in the area of the hidden marking. The thermochromic cover layer is opaque below its change temperature, hides the marking, and is translucent or transparent above its change temperature, enabling viewing of the marking. The thermochromic cover layer is pervious to radiation outside the visible spectral range and the marking layer absorbs radiation energy outside the visible spectral range, so that the hidden marking can be incorporated into the marking layer through the thermochromic cover layer by laser radiation of a wavelength outside the visible spectral range.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.