Abstract: A rotating shutter system for improving the resolution of a visual scene projected upon a spherical screen by a 360.degree. non-programmed visual display system. A rotating shutter, which has on its upper surface a plurality of opaque radial lines, is positioned within an annular probe of the 360.degree. non-programmed visual display system so as to improve the resolution of the annular probe. A direct current motor drives the rotating shutter at a predetermined rotational speed, and a feedback circuit maintains the rotational speed of the direct current motor at a constant value.

Abstract: A variable speed drive for controlling the movement of the zoom component of a zoom lens system such that the speed of zooming will be proportional to the amount of manual displacement of a control member. The same manually operable control member which controls the speed, the amount and the direction of zooming also controls the position of the focusing component so that focusing as well as selectively varying the speed and amount of zooming can all be effected by a single control member.