Light-guiding optical system, especially for motor vehicles

1. A light-guiding optical system for motor vehicles comprising at least one light source and a light guide for coupling and guiding light rays ( 10 ) emitted by the light source,

wherein the light guide comprises a decoupling surface on a rear side of the light guide and an output surface for an exit of light rays decoupled by the decoupling surface on an opposite front side of the light guide,

wherein the decoupling surface comprises first decoupling elements configured to decouple the light rays falling onto the first decoupling elements out of the light guide approximately in a pre-determined first output direction to fulfill a first light function and a second decoupling element configured to decouple the light rays falling onto the second decoupling element out ofthe light guide approximately in a pre-determined second output direction diverted from the first output direction to fulfill a second light function, and

wherein the second decoupling element is a pair of reflective surfaces comprising a second reflective surface and a third reflective surface that together form an obtuse angle and are configured for reflection of the light rays that fell on the second reflective surface, directly onto the third reflective surface, and a consecutive reflection of the light rays from the third reflective surface directly to the output surface and incidence of the light rays on the output surface at an angle excluding a total reflection, so that these light rays exit from the light guide through the output surface approximately in the second direction.

2. The light-guiding optical system according to claim 1 , wherein the light guide has an elongated shape, wherein the decoupling surface and the output surface are positioned in a longitudinal direction of the light guide.

3. The light-guiding optical system according to claim 1 , wherein the first decoupling element is a first reflective surface which is inclined towards the output surface in a direction from the light source and is configured for reflection of the light rays falling onto the first reflective surface directly to the output surface and incidence of the light rays on the output surface at an angle excluding total reflection, so that the light rays exit from the light guide through the output surface approximately in the first output direction.

4. The light-guiding optical system according to claim 1 , wherein in a direction from the light source, the second reflective surface is situated in a direct extension of the first reflective surface and a positional order in a direction from the light source is the first reflective surface, the second reflective surface and the third reflective surface.

5. The light-guiding optical system according to claim 1 , wherein the first reflective surface and the second reflective surface are connected to each other.

6. The light-guiding optical system according to claim 1 , wherein the second reflective surface and the third reflective surface are connected along a connecting line.

7. The light-guiding optical system according to claim 1 , wherein the decoupling surface further comprises a fourth reflective surface configured for reflection of the light rays falling onto the fourth reflective surface, directly towards the output surface and incidence of the light rays on the output surface at an angle, which will cause total reflection of the light rays from the output surface and further propagation of the light rays through the light guide, wherein the first reflective surface, the second reflective surface, the third reflective surface and the fourth reflective surface are in a positional order from the light source and are part of a reflective arrangement that repeats itself in a longitudinal direction on the decoupling surface.

8. The light-guiding optical system according to claim 7 , wherein the fourth reflective surface is approximately parallel to an opposite part of the output surface.

9. The light-guiding optical system according to claim 7 , wherein the connecting line lies on a hypothetical surface that is a direct extension, in the direction towards the light source, of the fourth reflective surface.

10. The light-guiding optical system according to claim 7 , wherein the light guide comprises a plurality of reflective arrangements, wherein lengths of the reflective arrangements are identical.

11. The light-guiding optical system according to claim 7 , wherein the light guide comprises at least two reflective arrangements having different lengths in order to achieve the required resulting appearance and homogeneity.

12. The light-guiding optical system according to claim 7 , wherein length of the reflective arrangement is approximately from 0.7 mm to 3.5 mm.

13. The light-guiding optical system according to claim 1 , wherein the second reflective surface makes an angle from 95° to 150° with the third reflective surface.

14. The light-guiding optical system according to claim 1 , wherein the first light function is a function of a tail light and the second light function is a function of a side clearance light.

15. The light-guiding optical system according to claim 1 , wherein the first output direction makes an angle of approximately 90° with the second output direction and is approximately parallel to a longitudinal axis of a vehicle.