GB1047505A - - Google Patents

Abstract

1,047,505. Panoramic cameras. FAIRCHILD CAMERA & INSTRUMENT CORPORATION. February 24, 1965, No. 7956/65. Headings G2A and G2J. In a panoramic camera in which the film is transported past a slit 13 at the focal plane of the objective 21 and a rotatable optical scanner in front of the objective 21 permits scanning through 180 degrees, instead of the scanner being in the form of a double-dove prism device, Fig. 2, (not shown), which after scanning the two forward quadrants proceeds to scan the two back quadrants which take in the sky and are usually mechanically occluded by the camera, the scanner is in the form of n prisms each having faces forming a dihedral angle of 360 degrees/n where n is an even integer greater than 2, corresponding apices being disposed at the axis of rotation, and the interfaces of the prism assembly being effective to transmit light rays incident thereon at an angle less than a predetermined angle and to reflect rays incident thereon at an angle greater than the predetermined angle. As shown four prisms 22-25 are provided and as the scanner rotates, the two desired forward quadrants are repeatedly scanned so that no waste of film results. To prevent ghost images appearing from rays such as G, Fig. 8, (not shown), anti-reflection coatings may be applied to the external surfaces of the prisms 22-25 and if still troublesome, thin films of transparent plane-polarizing material may be applied to interfaces 26, 27, the planes of polarization being perpendicular to one another.