VARIABLE FOCAL DISTANCE LENS HOLDER Russian patent published in 2016 - IPC G02B7/10 G03B17/02 

FIELD: machine building.

SUBSTANCE: tube assembly includes the first ring zoom containing the first projection; Guide ring located around the first ring zoom containing the first guide slot, through which passes the first projection, and the second guide slot; the second ring zoom containing a second projection and movable in axial direction; the first cylinder containing a guide Groove, in which the second projection is inserted; and the third projection passing through the second guide slot and located between the first ring zoom and second ring zoom; the second cylinder arranged around guide ring, containing fourth projection, the first section of the Groove, in which the first projection, and the second section grooves in the third projection, and carrying the first ring zoom and first cylinder; and outer cylinder arranged around the second cylinder and the third section grooves in the fourth projection.

EFFECT: technical result is providing high magnification, reduced length and width of the tube and number of parts.

10 cl, 6 dwg