METHOD FOR PROTECTING HOLOGRAMS FROM FORGERY AND DEVICE FOR AUTOMATIC CONTROL OF HOLOGRAM VALIDITY Russian patent published in 2005 - IPC

FIELD: holograms protection technologies.

SUBSTANCE: method includes recording a hidden image on hologram in form of two-dimensional matrix of light optical points, wherein individual check code is set in predetermined angles of matrix; also, for positioning protective hologram an image of point object is recorded on it, outside limits of mask aperture, and during reading of hidden image protective hologram is displaced until restored image of point object placed outside mask aperture, fits point aperture in micro-diaphragm, and until an electric signal with maximal amplitude is detected at output of positioning control photo-detector, which shows correctness of positioning of protective hologram.

EFFECT: higher efficiency.

2 cl, 7 dwg