Improvements in or relating to optical data insertion devices

摘要

A reflection barrier 30 is suitable for use with an optical insertion device of the type comprising a projector 23 operable to insert additional optical data into a capture aperture of an optical system so as to provide a combined image. The barrier has a primary filter 32 adapted to cover the capture aperture of the optical system, the primary filter has an aperture or cutaway portion 31 aligned with the light emitted by the projector into the capture aperture. The reflection barrier may be used in a thermal imaging device. The filter is arranged to minimise the reflected light so as not to draw attention to the user of the device. Lens spacer (33, figure 3) may also be provided to reduce the reflection of light from the projector.