Collapsible binocular telescope with adjustable internal focusing

摘要

The invention contemplates an improved binocular telescope construction of the variety wherein a bridge provides articulated connection of the two telescope systems, so that by folding at least one of these articulated systems back against a side of the bridge, the instrument may be compacted when not in use. The invention is particularly concerned with provision of a single focusing drive for the focusing optical elements of both telescope systems, the drive being operative regardless of the extent of articulated expansion or contraction of the bridge-connected systems. The invention also features provision of such focusing by movement of optical elements contained within the overall telescope-housing length, so that such length does not change in the course of focusing. Various embodiments are described.