Abstract: A varifocal lens assembly of simplified construction which essentially comprises a lens mounting for focusing adjustment, a second lens mounting and a third lens mounting cooperative with the second lens mounting for adjustment of the focal length and for correction of optical aberrations resulting from the displacement of the second lens mounting and an operating barrel for operating the first and second lens mountings, either independently or simultaneously. The operating barrel effects, when rotated, the focusing operation and, when axially moved, the zooming operation.

Abstract: A magnetic recording disc is made up for a rotating disc, a flexible sheet mounted on the rotating disc, a magnetic sheet carried by the flexible sheet for recording and reproducing signals by a magnetic head, and a holding means.The rotating disc has a first surface and a second surface indented from the first surface. The magnetic sheet is held together with the flexible sheet, on the first surface of the rotating disc by the holding means. The magnetic head is in close contact with the magnetic sheet over the second surface with the aid of the flexible sheet mounted on the rotating disc.