Conventional gaming apparatuses are susceptible to electromagnetic fields in the environment. Electromagnetic Compatibility (EMC) is the ability of an apparatus, device, unit, or system to function satisfactorily in its electromagnetic environment without reacting to electromagnetic disturbances in that environment. This encompasses both immunity to outside noise which allows the apparatus to function satisfactorily, and emission of noise which limits the introduction of intolerable disturbances.
Radiated emissions deals with the electromagnetic fields emitted by any electronic circuit that performs a switching sequence, and the emissions radiated increase if an antenna, which could be an I/O cable for example, is present. Conducted emissions refer to the noise that is generated into the power lines for the apparatus which causes interference at certain frequencies. Electrostatic discharge (ESD) is the static charge that can build up in normal operations to a level of several kilovolts which can stress and damage electronic components within the gaming apparatuses. Radio Frequency Immunity (RFI) is the ability of the gaming apparatuses to work undisturbed in an RF field (electromagnetic field).
Gaming regulatory agencies test for these various apparatus emissions and their immunity to electromagnetic fields. Certain jurisdictions have particularly rigorous tests that provide challenges in passing for gaming apparatus manufacturers. Conventional gaming apparatuses typically use metal housings to provide structural support as well as taking advantage of its shielding capabilities. However, portions of the housing or even panels in the gaming apparatuses' housing are made of plastic or glass materials that have poor shielding characteristics.
One area that has been found to be a large “hole” for emissions to penetrate the gaming apparatuses is the glass area of the apparatuses' housings. One attempt to reduce the emissions in the glass panels was in a number of prior art pinball machines manufactured and sold by IGT of Reno, Nev. more than one year prior to the filing of this patent that utilized a conductive coating of Indium Tin Oxide applied to a clear film that was placed next to the glass panel and inside the pinball machines. The use of the Indium Tin Oxide on the clear film did not provide satisfactory results in its ability to eliminate or sufficiently reduce the emissions through the glass panel of the pinball machine.