GB398647A - Optical reflecting device - Google Patents

Abstract

398,647. Reflectors. STœRTZ, E., 94, Rue de Levis, Paris. Oct. 4, 1932, No. 27529. Convention date, Oct. 8, 1931. [Class 97 (i).] A reflector for returning light along its direction of incidence comprises one or more units each consisting of a main element and at least two auxiliary elements of transparent material, each element being of right-angled triangular section and the elements being so arranged that the hypotenuses of the sections of the auxiliary elements are adjacent and parellel to the sides of the section of the main element which are at right angles to each other. Fig. 3 shows a unit consisting of the main element ABC and two auxiliary elements A<1> B<1> C<1>, A<11> B<11> C<11>. A ray i incident at right angles to the surface B C is successively reflected by the surfaces A B, A C, the emergent ray r being parallel to the incident ray. An oblique incident ray such as i<1> is returned parallel to itself after reflections at the surfaces A B, A<1> B<1>, A<1> C<1>, and A B, while a ray such as i<11> is returned parallel to itself after reflections at the surfaces A<11> B<11> and A<11> C<11>. The three elements are shown in contact, but in practice they are separated to enable the surfaces A B, A C to act as reflectors. Figs. 6, 7 and 8 show a reflector made up of a number of units as above described, the main elements being so arranged that the axes of any two adjacent elements are at right-angles to each other. These elements are all formed on a glass &c. plate P<1> and the auxiliary elements are all formed on a plate P<2> which fits over the plate P<1>, a packing member 1 being interposed to provide air spaces between the main and auxiliary elements. The plates are supported in a frame 2. The plates may be of circular or triangular form.