A dynamic non-contacting optical interface

In the mature civil aircraft simulator market, companies have been forced to remain competitive by paying careful attention to details such as quality, performance and cost. The military simulation market, however, is still developing and long term goals (extending to the year 2020) for training system performance have been proposed by the US Air Force. These postulate a requirement for deployable visual display systems with 20/20 vision (i.e. equivalent to normal corrected sight) to be in service by the year 2001. For helmet based systems, a constraint on developments is that current display sources are coupled to the helmet via a tethered and cumbersome optical link (such as a coherent optical fibre bundle). Alternative on-helmet display devices do not have satisfactory performance (resolution, colour or weight). It is not currently possible, therefore, to provide the high level simulation products that meet the market requirements for applications in military training and professional visualisation. The paper describes the work done to date in investigating the concept of a display system that utilises a non-contacting link between an image source and a helmet based display system. The work has been the basis of a TCS program between SEOS Displays Ltd and Kingston University. The paper discusses a number of the mechanical and optical problems that need to be overcome to make the project viable. The main mechanical problems are concerned with the high speed, accuracy and complexity of tracking required. The optical problems are concerned with the optical relay, relay/helmet interface and helmet/user interface