Abstract: Disclosed herein is a method that combines two different hologram origination processes in a single photoresist layer by using an interlayer to transfer structures exposed by electron beam lithography into overlapped with dot-matrix hologram areas, and fabricated holographic structures are replicated in multilayer polymer films. Dot-matrix technique is low cost process, which has high origination speed and can be used for the patterning of large areas of holograms with high diffraction efficiency. Electron beam lithography allows the formation of high resolution structures. The method allows combining these two technologies so that the final security device could contain electron beam patterned high resolution diffraction gratings, computer generated holograms, as well as dot-matrix laser patterned large hologram areas with high diffraction efficiency, providing an increased level of protection.
Type:
Grant
Filed:
February 18, 2021
Date of Patent:
December 19, 2023
Assignee:
Kaunas University of Technology
Inventors:
Viktoras Grigaliunas, Sigitas Tamulevicius, Mindaugas Andrulevicius, Tomas Tamulevicius, Egle Fataraite-Urboniene, Pranas Narmontas, Tomas Klinavicius, Dalius Jucius, Mindaugas Juodenas
Abstract: A storage target having a collector electrode formed in a striped or latticed pattern on a storage substrate which is fabricated from a single crystal of electrically insulating material. Preferably, the storage substrate is of a single rhombohedral crystal of aluminum oxide or of a single isometric crystal of magnesium oxide, spinel, or calcium fluoride.
Abstract: An electronic storage tube of the electron beam modulated type employing a target structure of the "coplanar grid" type in which the coplanar grid is a multilayered structure having at least one layer thereof which is more immune to ionizing radiation, such as X-rays, than at least one of the remaining layers, to yield a target structure in which erasure time and retention time are both significantly improved even though the stored pattern is repetitively read out.A method is also described herein for operating target structures of the type described hereinabove to take advantage of the above mentioned advantageous characteristics and thereby yield an electronic storage tube having operating characteristics not heretofore capable of being provided in conventional structures.
Abstract: A memory device and method is disclosed wherein positions of ions associated with a film are varied locally with respect to the film's surface by an electric field. A writing and erasing field is created by voltage modulating the film's conducting substrate in syncronization with low intensity electron bombardment of a local area of the film's surface by a scanning electron beam.The ion's position in the film varies the film's surface potential and alters the angular distribution imparted by its surface to primary diffracted and secondary emitted electrons. In the invention's read mode a scanning electron beam, combined with a detector discriminator, analyzes these emitted electrons to determine the surface potential at each address on the film thus reading out data stored in the film. A second means of reading out stored information utilizing detection of low energy electrons selectively diffracted by ions near the film's surface is disclosed.