Spherical lens for earth observation satellite TV system - has cone of optical fibres extending between lens and image reception surface

摘要

The lens (2) has a number of optical fibres (3) extending from the rear face. These optical fibres (3) initially curve outwards to a point (M) defined by a perpendicular plane and then curve back inwards so that their light output ends face a planar image reception surface (9). The lens (2) is formed in two hemispherical halves (21,22) their outer peripheral rims held by a holder (4), with an aperture stop plate (5) positioned between the halves (21,22). An intermediate lens (8) with front and rear faces having a centre of curvature coinciding with that of the spherical lens (2) is positioned in the gap between the rear face of the latter and the light input ends of the optical fibres (3). The image reception surface (9) may comprise the screen of a video camera.