GB1270560A - Searchlight apparatus - Google Patents

Abstract

1,270,560. Searchlights. INTERNATIONAL STANDARD ELECTRIC CORP. 16 July, 1969, No. 35769/69. Heading F4R. A searchlight comprises a light source 14 at the focus of a parabolic reflector 13, a first matrix 17 of relatively small converging lens elements 18 disposed in a plane normal to the axis of the reflector and having an outside diameter substantially the same as that of the reflector aperture, and a second matrix 24 of relatively small converging lens elements 25 parallel to and spaced from the first matrix and of substantially the same diameter. Each matrix has the same number of lens elements and each element is axially aligned with a corresponding element of the other matrix and has the same focal length as the other elements of the same matrix, the focal lengths of the elements of both matrices being the same and equal to the distance between the matrices. A grid-like structure composed of tubular elements 28 having the same cross-sectional shape, as the lens elements is disposed between the matrices to prevent "cross-talk" between adjacent pairs of lens elements. The lens elements may be of rectangular or circular shape and the matrix 17 may be movable axially to vary the shape of the beam. The source 14 may be a tungsten filament or xenon arc lamp; when the latter is employed the elements 28 may be replaced by a shield which prevents direct light from reaching the first matrix.