An Anti-counterfeiting Method of Dynamic-Effect Dot-Matrix Hologram

Dot-matrix holograms typically generate anti-counterfeiting patterns by arranging grating units with varying orientation angles in periodic or rule-based configurations. However, such regular arrangements are vulnerable to reverse engineering, thereby increasing the risk of counterfeiting. To address this limitation, we propose a novel dot-matrix hologram generation algorithm capable of producing dynamic diffractive effects. By precisely controlling both the orientation and period of each grating unit, the resulting diffraction pattern exhibits continuous motion in response to changes in illumination or viewing direction. In this approach, the orientation angle of each grating unit is determined by its spatial relationship to the target image, yielding a non-periodic and irregular distribution that significantly enhances resistance to imitation. Moreover, the algorithm is compatible with arbitrary input images and reliably produces pronounced dynamic behavior, thereby offering superior anti-counterfeiting performance and enhanced visual distinctiveness. The dynamic motion of the diffractive pattern has been experimentally validated through embossed holography, which confirms the practical effectiveness of the proposed method in improving the security and functionality of dot-matrix holograms.