apparatus and method for making a security hologram with multi-images indifferent viewing direction on a small area

摘要

Abstract: The prior artwork for a Dot-matrix hologram is always animated by a computer instead of a man made sculptured model. For a computer graphic software, it is very easy to interlace several bitmap graphics ona small area. So, if we generate an interlaced graphic and transfer the bitmaps to corresponding gratings which diffract the illumination light to a specific direction with respect to each individual graphic, then it will have several viewing images in different view angles. Hologram has special light characteristics that are difficult to duplicate, so it has intrinsic advantage for anti-counterfeiting application. For more guarantee of security to protect the value paper from the fraud activity. We use a more complex and delicate multi-image hologram to hold back the ambition of copycat. In this paper, will describe how to transfer the images that generated by computer to a hologram. The concept for interlace graphics, and the apparatus that is easy to generate the dot grating with respect to each bitmap in the image, and the practical samples that made by this technology for anti-counterfeiting purpose. !7