FR2782778A1 - Centralized lighting system using light guides has central strong light source and guides with de-polished ends diffusing light output - Google Patents

Abstract

The system uses de-polished light guide ends to diffuse light. The centralized lighting system includes a main light source (2) and several light guides. These optical devices each comprise a guide (4) having a core surrounded by a sleeve (6) with one end adjacent to the source, and the second end linked to a secondary light distribution device. The core is stripped of its sleeve for a section of its length at the second end in order to diffuse light outwards over this range of length. The stripped section may be de-polished either by mechanical abrasion or by chemical attack in order to improve its ability to diffuse light.

Description

Centralized lighting system comprising at least one guide

  optic and optical guide for centralized lighting system.

  The present invention relates to a centralized lighting system comprising a main light source emitting a luminous flux; at least one optical system for using this light flux remote from the main source; an optical guide associated with said optical use system, this guide consisting of a core surrounded by a sheath and having an input end which receives the light flux from the main source and an output end which transmits the light flux received towards the optical system of use with which it is associated so as to constitute a secondary light source. Centralized lighting systems have the advantage of making it possible to have multiple secondary light sources from a single main source, which can be installed, for example, in very

  miscellaneous in a motor vehicle.

  A centralized lighting system of this type is known from document FR 2 726 069. It comprises a main light source, and optical guides which receive the light from the main source and direct it to remote points of use constituted by surfaces

reflective dishes.

  However, in this device, light is emitted along the axis of the optical guide. The luminous flux must therefore be

  redirected before being used in the parabolic reflector.

  This is why mirrors are provided located at the focal point of a parabolic reflecting surface, which receive the light leaving the optical guide and which reflect it towards the parabolic reflecting surface. This increases the complexity and the

system cost.

  The present invention relates to a centralized lighting system with optical guides which overcomes this drawback. It avoids the use of additional devices, such as mirrors, to redirect the light

to the sources of use.

  This result is achieved by the fact that the optical guide is stripped over a certain length at its outlet end to obtain a stripped segment optically treated

  so as to spread the light over its entire length.

  The stripped segment can be etched by abrasion or

chemical treatment.

  Thanks to this characteristic, the stripped segment of the optical fiber behaves like a secondary source of cylindrical light, like the filament of a conventional incandescent lamp which emits light in all directions. In one embodiment, the stripped and treated segment of the optical guide is implanted in an optical use system traditionally operating with a filament lamp such as a reflector of the parabolic type, a reflector

of the elliptical type.

  The lighting system according to the invention may include

  several optical systems juxtaposed.

  Furthermore, the invention also relates to an optical guide comprising a core surrounded by a sheath, and having an input end which receives the light flux from the main source and an output end which transmits the received light flux to the optical system. of use with which it is associated, characterized in that it is stripped over a certain length at its outlet end to obtain a stripped segment optically treated so as to scatter the light on

its entire length.

  Other features and advantages of this

  invention will still appear on reading the description

  of an exemplary embodiment made with reference to the appended figures in which: - Figure 1 is a perspective view which illustrates the principle of a centralized lighting system with optical guides according to the prior art; - Figure 2 is a perspective view which illustrates the principle of a centralized lighting system with optical guides according to the invention; - Figure 3 is a perspective view of an optical system according to the invention in which the optical guide is located in a parabolic reflector; - Figure 4 is a perspective view of an optical system according to the invention in which several reflectors are juxtaposed. Figure 1 illustrates the principle of a centralized lighting system with optical guides. The lamp 2 constitutes a main light source. An optical guide 4 consists of a sheath 6 and a core 8. The optical guide has an inlet end 10, located near the

  lamp, and an outlet end 12, remote from this lamp.

  The light received at the entry end of the optical guide is transported to the exit end 12 which thus plays the role

a secondary light source.

  As can be seen, the light 14 is emitted in the axis of the heart at the outlet end. It is therefore necessary to provide specular surfaces, such as mirrors 16, to redirect it, for example to a reflector

parabolic (not shown).

  Figure 2 illustrates the principle of a system

  centralized lighting with optical guides according to the invention.

  We find the lamp 2, which constitutes a main light source, the optical guide 4, with its inlet end 10 and its outlet end 12. The outlet end of the optical guide is stripped over a certain length 18 so as to

  obtaining a stripped segment 19, that is to say a segment without a sheath.

  This segment is optically treated so as to produce approximately constant light leaks over its entire length. The segment 19 is for example etched by abrasion or by a chemical treatment. Thus, the stripped segment directly constitutes a cylindrical secondary light source. It behaves like an incandescent filament which emits light in all directions as shown by

arrows 21.

  As shown in FIG. 3, the stripped segment can be placed at the focal point of a parabolic reflector 20, the optical guide passing through the reflector substantially along the axis of the parabola. As shown in FIG. 4, the advantage of centralized lighting systems with optical guides, namely allowing the juxtaposition of optical systems (four parabolic reflectors in the example shown) is preserved.

Claims (10)

  1. Centralized lighting system comprising a main light source (2) emitting a luminous flux; at least one optical system for using this light flux remote from the main source (2); an optical guide (4) associated with said optical system of use, this guide consisting of a heart (8) surrounded by a sheath (6) and having an inlet end (10) which receives the light flux from the main source (2) and an output end (12) which transmits the received light flux to the optical use system with which it is associated so as to constitute a secondary light source, characterized in that the optical guide (4) is stripped over a certain length (18) at its outlet end (12), to obtain a stripped segment (19) optically treated   so as to diffuse the light over its entire length (18).   2. Lighting system according to claim 1, characterized in that the segment (19) stripped and treated of the optical guide (4) is implanted in an optical system of use   (20) traditionally operating with a filament lamp.   3. Lighting system according to claim 2, characterized in that the optical use system (20) is a reflector of the parabolic type.   4. Lighting system according to claim 2, characterized in that the optical use system (20) is an elliptical type reflector.   5. Lighting system according to one of claims 1   to 4, characterized in that the stripped segment (19) is etched by abrasion.   6. Lighting system according to one of claims 1   to 4, characterized in that the stripped segment (19) is frosted by chemical treatment.   7. Lighting system according to one of claims   previous, characterized in that it comprises several systems optics (20) juxtaposed.   8. Optical guide comprising a core (8) surrounded by a sheath (6), and having an input end (10) which receives the light flux from a main source (2) and an output end (12) which transmits the light flux received to an optical system of use with which it is associated, characterized in that it is stripped over a certain length (18) at its outlet end (12), in order to obtain a stripped segment (19) optically treated so as to diffuse the light over its entire length (18).   9. Optical guide according to claim 8, characterized   in that the stripped segment (19) is etched by abrasion.   10. Optical guide according to claim 8, characterized in that the stripped segment (19) is etched by chemical treatment.