The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 13, 2005
Filed:
May. 06, 2003
Stephen P. Mcgrew, Spokane, WA (US);
Sally-anne Carver, Aldershot, GB;
Stephen P. McGrew, Spokane, WA (US);
Sally-Anne Carver, Aldershot, GB;
New Light Industries, Ltd., Spokane, WA (US);
Abstract
An anticounterfeiting device comprising a surface relief structure having both diffractive and polarizing properties. Polarization of reflected light is controlled by the orientation and composition of a fine grating structure whose shortest period is substantially smaller than the wavelength of visible light; and diffraction is controlled by a longer period component of the grating structure having a second orientation. Presence and arrangement of the polarizing properties of the device are detected by illuminating the device with polarized light and viewing the reflected light, or by illuminating the device with unpolarized light and viewing reflected light through a polarizer. Because such a device is difficult to copy or reverse engineer precisely, the authenticity of the device can be judged by the presence and arrangement of the polarization properties and the diffraction properties in the device.