Patent ID: 7319551

Claim:
A maskless optical device based on interferometric lithography to generate an interference pattern within selected areas of a photosensitive material ensuring that the surrounding area is not affected by light, producing diffractive optical variable image devices for security, comprising: a first optical channel and a second optical channel at an angle for interfering with the photosensitive material; the first optical channel comprising a first imaging lens for producing an image from a first object at an image plane; the second optical channel comprising a second imaging lens for producing an image from a second object at the image plane, and wherein the device complies with the Scheimpflug rule and the Hinge rule; wherein the interference pattern comprises the images of the first and second objects; wherein the time needed to register a complete polygonal pattern is linearly proportional to the number of interference patterns specified for the reference geometry and not to the overall area of the optical device.