Borescope with simultaneous video and direct viewing

摘要

An assembly is described for connection to a borescope to simultaneously provide a virtual image for direct viewing by an observer and a video image for viewing on a display. The assembly ( 10 ) comprises a body ( 12 ) with a distal end for connection to an insertion tube of a borescope and a proximal end providing an eye piece into which an observer may look. The body contains a relay lens ( 16 ) and an ocular lens ( 18 ). A beam splitter ( 28 ) is mounted in the optical path between the relay lens ( 16 ) and the ocular lens ( 18 ) and diverts a proportion of light received from the relay lens ( 16 ) to an image-to-video conversion device ( 30 ) mounted laterally to the optical path. The ocular lens ( 18 ), beam splitting device ( 28 ) and the image-to-video conversion device ( 30 ) are all located in a common mounting ( 38 ) which can be translated in a direction parallel to the optical path to allow for focussing.