Abstract: An apparatus for identifying fake fingerprints has electrodes disposed along a platen surface of a fingerprint scanner and whether or not the skin of one or more fingers presented to the surface are real and alive is determined in accordance with analysis of electrical signals received from the electrodes. Electronics of the apparatus determines one or more liveness parameter(s) in accordance with signals received from electrodes. Information from an image of the fingerprint may be used to select which electrode signals to use for liveness detection. To further confirm the presence of a live finger(s), additional liveness parameter(s) of the pulse and/or temperature may also be sensed. The skin may be one of in contact with the platen of the fingerprint scanner, separated from direct contact with the platen's electrodes by an insulating layer or a pad, or not in physical contact with the platen or a pad thereupon.

Abstract: Molded silicone rubber sheets with optical quality surfaces and methods for making the same. The silicone rubber sheets are made by molding liquid silicone rubber in a mold. In embodiments, the mold forms parallel optical quality flat surfaces. In one embodiment, a stiffening plastic is molded in the middle of the silicone rubber sheet between the parallel optical quality flat surfaces. In another embodiment, the mold forms one optical quality flat surface while the surface parallel to the optical quality flat surface is bonded to a prism.

Abstract: Devices and methods for applying heat to a platen of a biometric image capturing device are described that remove and prevent the formation of excess moisture on the platen. These devices and methods prevent undesirable interruptions of total internal reflection of a prism that result in biometric images having a halo effect. In embodiments of the invention, an electrically conductive transparent material is used to apply heat to the platen. In other embodiments, resistive heating elements attached to non-optical areas of the platen (e.g., the ends) are used to apply heat to the platen. Heater assemblies according to the invention can be used to heat an area where a biometric object is placed, or an area adjacent to where the biometric object is placed, to remove and prevent the formation of excess moisture on the platen.

Abstract: Devices and methods for applying heat to a platen of a biometric image capturing device are described that remove and prevent the formation of excess moisture on the platen. These devices and methods prevent undesirable interruptions of total internal reflection of a prism that result in biometric images having a halo effect. In embodiments of the invention, an electrically conductive transparent material is used to apply heat to the platen. In other embodiments, resistive heating elements attached to non-optical areas of the platen (e.g., the ends) are used to apply heat to the platen. Heater assemblies according to the invention can be used to heat an area where a biometric object is placed, or an area adjacent to where the biometric object is placed, to remove and prevent the formation of excess moisture on the platen.

Abstract: Molded silicone rubber sheets with optical quality surfaces and methods for making the same. The silicone rubber sheets are made by molding liquid silicone rubber in a mold. In embodiments, the mold forms parallel optical quality flat surfaces. In one embodiment, a stiffening plastic is molded in the middle of the silicone rubber sheet between the parallel optical quality flat surfaces. In another embodiment, the mold forms one optical quality flat surface while the surface parallel to the optical quality flat surface is bonded to a prism.

Abstract: A method for odorizing natural gas in the pipeline utilizes bypass piping in conjunction with a liquid odorant storage tank. The bypass line causes a precisely known volume of bypass gas, saturated with odorant, to enter the gas line at regular intervals determined by gas flow through the line. Natural gas, having a known pressure higher than the pipeline pressure, is provided to the bypass line, and controlled by a control valve. The flow characteristics of the control valve are known in advance, so that opening the valve for a known time period allows a known quantity of bypass gas to flow through the valve. A controller monitors the gas line, and each time a pre-determined quantity of gas flows through the line, the control valve is opened for the calculated time. The bypass line is connected from the control valve to the odorant tank, and from the odorant tank to the gas line.

Abstract: A fixture capable of accurately manipulating a workpiece through a circular arc is provided. Various concepts useful in the formation of a cylindrical surface on the workpiece are developed. One fixture described includes a pair of opposing spherical surfaces which are restricted in degree of movement by a key extending from one surface into a slot in the opposing surface.

Abstract: A linear capillary orifice injector for producing a chemical reaction in a combustion chamber is disclosed. The orifices are judiciously arranged to form a discrete pattern for achieving a high degree of shear mixing while attaining a uniform temperature and species profile particularly necessary for chemical lasers.