LENS TO CHANGE THE SIZE OF THE IMAGE Russian patent published in 2018 - IPC G02B7/10 G02B15/163 

FIELD: optics.

SUBSTANCE: lens consists of an optical portion including first, second and third lens units and a movement mechanism comprising a front and a rear portion and two cylindrical rings disposed there between with rectilinear grooves disposed along the optical axis. Front part is made of a rim in the form of a cylindrical element, a holder and a frame in the form of a cylindrical element for the first and second lens units and is installed with a possibility of back and forth movement along the optical axis. Rear part is made of a stationary body in the form of a cylindrical element for the third lens unit. Keys are installed on the outer cylindrical surface of the first cylindrical ring. Outer cylindrical surfaces of the first cylindrical ring and the stationary body are provided with stops. First and second cylindrical rings are mounted with the possibility of reciprocating rectilinear displacement along the optical axis by means of keyed connections.

EFFECT: technical result is a change in the image scaling in a wide range, a reduction in the de-alignment of optical elements to ensure high image quality.

23 cl, 14 dwg