Face plate graticule
AssigneeThe Rank Organisation Limited
InventorsDavid George Anthony Demaine, David Gordon Norrie
Life of this patent
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Abstract
In an optical display system, information recorded on a face plate or like optical element is injected into a main optical path by means of a standby sight device comprising a lens unit and a flexible fibre optic bundle having a numerical aperture sufficiently large to cover the maximum acceptance angle of the lens unit.
Claims6
In an optical system having a stand-by sight device comprising a flexible fibre optic bundle, a light input unit at one end of the bundle, a fibre distributing element at the other end of the bundle, and a graticule on the output face of the distributing element, and a lens unit through which an image of the graticule is projected via a combining mirror into the user's field of view, the improvement that the distributing element has a face plate having an outer face with which the output ends of the fibres are coplanar and on which is deposited a dark ground graticule, the face plate bearing the graticule and the flexible fibre optic bundle having a numerical aperture sufficiently large to cover the maximum acceptance angle of the lens unit.
In a head-up display having a stand-by sight device comprising a flexible fibre optic bundle, a light input unit at one end of the bundle, a fibre distributing element at the other end of the bundle, and a graticule on the output face of the distributing element, and a lens unit through which an image of the graticule is projected into the pilot's field of view, the improvement that the distributing element has a face plate in the form of a slotted mask, the output ends of the fibres terminating in the slots and the outer face of the mask, and a dark ground graticule being directly deposited on said mask face.
Dependencies are inferred from the claim text.