Platen heaters for biometric image capturing devices

摘要

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.