Molded hologram apparatus method and product

#This application claims the benefit of U.S. Provisional Application No. 60/284,513, filed April 2001.

#Holographic images are well known. The holographic images may be used for decoration or security purposes. Holographic images may be found in credit cards, where they are often found in films laminated within the cards. Currency may have holographic images. Products and parts of products may have holographic images to avoid counterfeiting. When film is used for the holographic images, problems of counterfeiting continue. Recent attempts have been made to incorporate holographic images directly in the surface of products. Holographic films are created and etched, leaving irregular surfaces. Metal films are sputtered on the irregular surfaces of the films, and the films are removed, leaving an irregular surface on the metal.

#Difficulties with quality of the holograms on surfaces of the articles persist in holographic images produced by in molded holograms.

#FIG. 1 is a schematic cross-sectional representation of a mold insert for producing the hologram in a molded part.

#FIG. 2 is a perspective detail of the mold insert.

#FIG. 3 is a perspective top view of a mold insert.

#Referring to the drawings, FIG. 1 shows the cross section of a mold 1 having an upper half 3 and a lower half 5 with a mold cavity 7 formed between the halves.

#In-mold hologram insert assembly 10 is inserted in a recess 9 in the lower half. The mold insert 10 has an outer frame 11, with sidewalls 13 surrounding an insert plug 15. The side walls 13 have inward extensions 17 at their tops 19 to hold the hologram shim 21 on top of the plug 15, by engaging outer edge portions 23 of the shim which overlie outer edge portions 25 of the upper surface 27 of the mold plug 15. The lower surface 29 of the mold plug is supported on a compression layer plate 31, which is contacted by the tops 33 of four or more springs 35 which are contained in cylinders 37 at the bottom of recess 9 in the lower mold half 5. In addition to or instead of the springs 35 the cylinders 37 have volumes 39 filled with air or hydraulic fluid under pressure.

#A compressible recovery material 41 which may be a resilient elastomeric material or a spring plate underlies the plug and preferably underlies the frame to cooperate with the springs 35 and air or hydraulic fluid in cylinders 39. Pressure in the mold tends to move the frame 11 and plug 15 downward in the recess 9 during injection of material in the mold cavity 7. After injection the plug or plug and outer frame move upward to follow the molded part as any shrinking of the molded part occurs, thereby pressing the hologram and shim continuously against the molded part until the molded part is fully set and is removed from the mold cavity 7 after opening the mold halves 3 and 5.