Projection apparatus for use in an image transducing system

Claim 1

An image projecting apparatus for use in an image transducing system, wherein an image of a substantially linear region, such as a line of indicia, having a length L is projected from a display area to a target area of an incremental sensing device such as a vidicon tube, or of a source of illuminating radiation such as a cathode-ray tube, wherein within said system the display area corresponding to the linear region has a length to width ratio substantially greater than the length to width ratio of the target area, which image projecting apparatus comprises an optical system of lenses and mirrors disposed adjacent the display area and the target area for controlling the size, focus and position of the projected image, characterized by the feature that said optical system is disposed to provide at the target area an image optimumly covering the target area which is at any one time a relatively short segment Delta L of the image at the display area, wherein said optical system includes a mirror which is rotatable to scan across the display area to vary over a period of time the segment Delta L being instantaneously provided at the target area in order to display the entire region across the target area over the period of time.