Light optical system, especially for information, advertising illumination or decorative purposes

A method of illuminating a planar light conductor having a first surface and a second surface and a transparent body therebetween with a light source, comprising the steps of:

• attaching an injector comprising a wedge-shaped body made of transparent material having a refractive index higher than air to the first surface of the planar light conductor, forming an optically homogeneous optical interface, the input side of the injector being shaped such that light entering the injector through the input side is brought into focus at a point inside the planar light conductor or behind it;
• directing light from the light source into the injector using a light guide, such that light output from the light source is guided into the injector by the light guide and is conducted into the planar light conductor through the optically homogeneous optical interface, and is distributed through the planar light conductor by internal reflection within the body of the planar light conductor.

A method of illuminating a sign attached to a surface of a window, comprising the steps of:

• attaching an injector comprising a wedge-shaped body made of transparent material having a refractive index higher than air to a surface of the window, forming an optically homogeneous optical interface, the input side of the injector being shaped such that light entering the injector through the input side is brought into focus at a point inside the window or behind it;
• directing light from a light source into the injector using a light guide such that light output from the light source is guided into the injector by the light guide and is conducted into the window through the optically homogeneous optical interface, and is distributed through the window by internal reflection, illuminating the sign attached to the surface of the window.