Patent ID: 8097324

Claim:
An optical article comprising: an optical data layer storing data; a mark comprising a first optically-detectable spot and a second optically-detectable spot disposed over the optical data layer; wherein the first optically-detectable spot comprises a first electrochromic material configured to undergo an optical state change at a first threshold voltage and the second optically-detectable spot comprises a second electrochromic material configured to undergo an optical state change at a second threshold voltage, and wherein the second threshold voltage is higher than the first threshold voltage; wherein the mark is configured to transform the optical article from a pre-activated state, in which the data is not optically accessible, to an activated state, in which the data is optically accessible, upon interaction with an authorized activation signal comprising a voltage at or above the first threshold voltage and below the second threshold voltage; and wherein the mark is configured to transform the optical article from the pre-activated state to an incorrectly activated state, in which the data is not optically accessible, upon interaction with an unauthorized activation signal comprising a voltage at or above the second threshold voltage.