Retroreflective element having a security element

A method for orientation of a retroreflective element, the method comprising the following steps:

• i. providing the retroreflective element, wherein the retroreflective element comprises a regular arrangement of multiple reflective triples, each triple having first, second, and third side surfaces that form an angle between 88° and 92° relative to one another, wherein at least a first selected triple in the arrangement has a first security element having at least one diffractive structure on the first side surface of the first selected triple, and wherein the first security element has a modulation depth selected so that the first security element is imperceptible when the retroreflective element is illuminated at an illumination angle <10°;
• ii. illuminating the retroreflective element at a predetermined illumination angle, and observing and evaluating a received signal at a predetermined observation angle;
• iii. changing a rotation angle ε in increments;
• iv. comparing a received color value of the first security element with a predefined color value, wherein the color value is an absolute value of a vector to a color location;
• and
• v:
• repeating steps iii and iv until the received color value agrees within a tolerance with the predefined color value.

A retroreflective element comprising a regular arrangement of multiple reflective triples, each triple having first, second, and third side surfaces that form an angle between 88° and 92° relative to one another;

• wherein at least a first selected triple in the arrangement has a first security element having at least one diffractive structure on the first side surface of the first selected triple;
• wherein the first security element has a modulation depth selected so that the first security element is imperceptible when the retroreflective element is illuminated at an illumination angle <10°;
• wherein at least a second selected triple has a second security element having a second diffractive structure;
• and
• wherein a line distance of the second security element is between 1.01 and 2 times the line distance of the first security element.

A retroreflective element comprising a regular arrangement of multiple reflective triples, each triple having first, second, and third side surfaces that form an angle between 88° and 92° relative to one another;

• wherein at least a first selected triple in the arrangement has a first security element having at least one diffractive structure on the first side surface of the first selected triple;
• wherein the first security element has a modulation depth selected so that the first security element is imperceptible when the retroreflective element is illuminated at an illumination angle <10°;
• wherein the first selected triple has first security elements on the first, second, and third side surfaces, respectively;
• and
• wherein the modulation depth of the first security element of the first side surface differs from the modulation depth of the first security element of the second side surface, and the modulation depths of the first security elements of the first and second side surfaces differ from the modulation depth of the first security element of the third side surface.