Vision sensors and displays are often used in adverse environments. For example, such sensors and displays may be used in cold conditions, where icing occurs on portions of the front of the sensor or display, and/or a low surface temperature may prevent the proper operation of electronics at the window or display image producing mechanism. Conductive thin films may be used for heating the sensor or display to increase surface temperature and/or prevent the formation of ice. When used for heating, an electrical current is run through the thin film. The thin film for heating is often cut into serpentine strips, or left as a single sheet, where heating current flows from the top to bottom of the display, or from left to right. Further, the conductive thin film may be located only around the perimeter of the display or window area, as that is where, due to thermal physics, most of the heat is often needed to be applied.
The sensors and displays may also be in an adverse environment where electrical components of the displays, enclosed sensors and/or enclosed electronics are subject to undesired electromagnetic energy, which can produce EMI. The sensors and displays may also need to prevent the radiation of electromagnetic energy that is sourced by the active electronics they contain to ensure compliance with applicable EMI emissions standards and to prevent interference to radio receivers. Conductive thin films may also be used to provide EMI shielding. In the case that both heating and EMI shielding is needed, the serpentine strip, perimeter only, and single sheet arrangements have long non-conductive openings associated with the conductive thin film, and in the case of the perimeter-only heater, a large non-conductive area in the center. In these cases the thin film provides very little EMI shielding at high frequencies. Thus, if both EMI shielding and heating are needed, two thin films are typically used for the sensor and displays, one film for heating, and another for EMI shielding. Such a design, however, requires the added complexity and cost of two thin films, as well as reducing the transmission of light and infrared energy and introducing distortion into these spectra.