DOOR EYE-SIGHT Russian patent published in 1997 - IPC

FIELD: wide-angle door eye-sight reinforced and standard doors, 45 to 90 mm thick, at a large field of view. SUBSTANCE: the eye-sight has a five-lens optical system including a three-element objective lens and a doublet eye-piece with a large air gap. The first element of the objective lens is rigidly fastened in the body location point by a tapered nut, the other two, as well as both lenses of the eye-piece, through intermediate bushings are spring-loaded to the flat end face to the first element. The door eye-sight has similar curvature radii of the biconcave and flat-concave lenses of the objective lens, as well as a symmetrical design of the biconcave lens of the objective lens and both lenses of the eye-piece. EFFECT: improved design. 3 cl, 3 dwg