Coupler for directly coupling light from main source into fibre=optic waveguide bundle

摘要

The device provides direct coupling of the light from a main source particularly a Halogen or Xenon lamp, into a fibre optic waveguide bundle (2). The individual fibres of the bundle (2) are fed to a display device, e.g. in traffic changing displays or in railway systems. A secondary light source (4) is provided in case the main source (1) fails. The output light bundle of the secondary source (4) can be coupled into the waveguide bundle (2) by means of a deviation mirror (5). Preferably, a hollow cube (3) is provided with two transparent outer surfaces to which the incident side of the waveguide (2) and the main source (1) are fastened, such that their optical axis are aligned. The secondary source (4) is arranged at an angle to the main source (1) on another transparent side. On operation of the secondary source (4), the mirror (5) is folded out at an angle of 45 degrees to the source (4) and the waveguides (2). The mirror axis passes through an intersection point (6) near the light entry surface (22) of the waveguides (2). This point (6) is determined by the distance of the reflective edge of the main source (1) from the incident surface (22) of the waveguides (2) and by the diagonal (D) of a surface (31) of the cube (31) parallel to the surface spanned by the reflection axes (A1, A2) of the two sources (1, 4). The axis of rotation of the mirror (5) runs perpendicular to the surfaces spanned by the reflection axes of the sources (1, 4).