FR2716954A1 - Fiber optic lighting device with transparent or translucent volumes. - Google Patents

Abstract

Device for predictably diffusing light transmitted by an optical fibre in a non spheroidal diffusing volume or a plurality of such volumes, without essentially affecting the transparency, translucence or mobility of said volumes. Volumes such as (2 to 8) are supplied by a bundle of optical fibers (1) that are usually embedded in the filler material which joins or supports said volumes. Volumes such as (3) remain moveable, even though they act as diffusors. The devices of the invention are especially useful in producing lighting, decorative and signalling effects.

Description

The present invention relates to fiber lighting devices

  optics of transparent or translucent non-spheroidal volumes, the wavelengths used being light waves 05 or close to the visible spectrum. The devices of the present invention fix the relative positions of the generator of the optical fiber or the bundle of fibers with respect to the surface of the diffusing volume placed at the end.

fiber.

  The optical fiber allows the propagation of a luminous flux thanks to a multitude of total reflections on its wall. Transmission takes place without thermal conductivity (cold light). The angle of opening of the light beam is normally of the order of 70 degrees and can commonly reach degrees. The fibers have limited flexural strength. Their radius of curvature cannot normally be less than ten times the diameter of the protective sheath. The use of optical fiber to transport the radiation supplied by a "light box" supplying one or more bundles of fibers makes it possible to separate the light source from the volume to be illuminated, with advantages in terms of safety, source maintenance, possible selection of wavelengths by suitable filters, the operation of which is programmable. On the other hand, the punctuality of the beam leaving the fiber or the bundle of fibers constituting a channel is generally not

  compatible with the requirements of domestic, decorative, public or industrial lighting, hence attempts to use fibers35 with diffusing volumes, homogeneous or not, out of glass or other transparent or translucent materials.

  The projects currently treated normally come from aesthetic designs by architects, without any directive being given to them concerning the technology and standards of the a05 devices to be used to obtain the desired effects, light floors for example. The realization is then very problematic, completely original therefore costly and at the limit of the admissible safety standards for lack of 10 sufficient developments, because too costly

  with regard to the turnover concerned.

  The same results or better results could often have been obtained from standardized and secure volumes (glass blocks for example), suitably implemented according to the devices of the present invention which -Fixes in the most interesting cases the positioning between the fiber outlet and the diffusing volume for specific effects. The present 720 invention also allows the standardization of panels of defined characteristics. The use of these devices allows, for example, an architect to design his plans on sound bases guaranteeing the desired effect, the additional studies25 during the realization only relating to adjustments of detail in order to optimize the yields. For the purpose of simplification and generalization, the present invention refers to diffusing volumes having a shape such that

  we can appreciate the notions of thickness and singing as opposed to spheroidal volumes.

  Commercial glass blocks, widely tested and standardized, are therefore a restriction of this general notion of volumes; they are therefore concerned by the present invention.

  Each position of the longitudinal axis of the fiber outlet (generator) relative to the tangential plane of the surface of the volume considered at the central point of impact of the radiation beam is characteristic of a particular device providing the solution to a need. precise lighting. The ippacts of the light beam directed into the cha t (thickness) of the diffusing volume are 1) characteristic of a first group of devices providing uniform lighting without dazzling the observer looking at the useful surface of the diffusing volume. In addition, the fiber end being in this configuration parallel to the main plane of the volume, it is possible to accommodate the fiber around this volume without constraining it by radii of curvature that it would not support. Under these conditions, a juxtaposition of elementary volumes is possible to form panels whose conductors are housed in the joints. One can consider for example the pre-assembly in the factory of particularly worked modules which can be assembled very easily on site. The positioning of the optical fiber outlet in the angle of a diffusing volume, a block for example, provides the additional advantage of a very covering uniform diffusion on the main surface, because the angle in which this diffusion takes place is slightly greater than the opening angle C3 of the beam leaving the fiber. Thus, the right angle of a glass block for example can be completely covered by the diffusion of the beam emitted from a standard fiber opening 70 degrees. It is therefore possible to group in a single disft-positive unft5 at a junction point the fibers feeding four blocks, or more if their

form lends itself to it.

  -4- On the basis of optical fibers wired in the joints between elementary volumes of the panels can be assembled. These panels can be standardized and modular. They can constitute decorative patterns and take advantage of all the developments in optical fiber such as for example the use of filters selecting wavelengths. Although not using the possibility of transparency in natural light, the panel placed or fixed to the ground and its remote light box, all belonging to the same device, have certain advantages compared to standard recessed luminaires, this in terms of electrical safety, the elimination of a large part of the heat-generating stresses and the possibility of using secure and standardized pavers, often self-supporting. They can also be less expensive than transparent or translucent panels, because the bundles of fibers supplying the various elementary volumes can extend towards the bottom of the space between the volumes and behind

  these. Luminous ceilings can also benefit from identical normally opaque assembled devices.

  The positioning of the fiber outlet perpendicular to the plane of a main face dazzles the observer placed opposite at normal powers, but this effect can be used to draw attention, by limiting for example if necessary the emission power of the light box. If necessary, you can use colors generated by the filters in the box. Since the optical fiber is not secured to the diffuser, it is possible to momentarily move it away without

  affect the reliability of the device.

  It is a solution for making windows whose

  the opening accommodates use as a diffuser when the field of the tile returns to its face position. a fiber outlet (for example at night), in the configuration described above as providing great visual comfort.

  Three figures have been produced in addition to the description above. Figures 1 and 2 schematically analyze the different versions of the device to adapt it to the desired effects. Figure 3 shows an example of the possibility of

  positioning of the fibers in the joints between diffusing volumes, without subjecting them to twisting, while grouping the fibers supplying an area.

  Figure 1 shows schematically the diffusing surface in the plane of its main faces. The arrows numbered 1 to 4 represent characteristic positions of the generator at the outlet of the optical fiber, in planes parallel to the main surfaces and passing through the volume. Such positions ensure maximum diffusion in the volume with minimal glare, thus allowing appreciable visual comfort for the observers facing the main surface. The oblique positions relative to the surface of the field allow modular special effects thanks to frosting, sandblasting or the use of colored filters on emission for example. The particular positions in the angles such as 1 allow maximum uniformity diffusion over the main surfaces, the diffusion possibly being uniform for a diffuser angle of value slightly greater than. i5 the opening of the fiber output light beam, normally between 70 and 130 degrees depending on the

  conductors provided. For a diffusing volume having an overall symmetry with respect to the bisector of the angle supplied, the optical fiber outlet 40 must be aligned on this bisector.

  It is even possible to correct the distribution imperfections due to the elongated diffusers by experimentally orienting the fiber outlet by rotation from an angle to around the point of impact 05 in order to bring the axis of the flow closer to the median axis of the volume (at the factory during preparation or

  settings for example). This lighting of the volume by an outgoing angle also has the advantage of allowing the grouping around a point of the fibers intended to supply several volume elements constituting a mosaic.

  Figure 3 shows schematically this possibility of grouping power supplies, often very interesting in terms of costs. It can be seen in this diagram that it is easy to find paths of fibers up to the angles avoiding excessively pronounced curvatures. Note that a fiber supply on the flat parts of ch.-Jt5 of the elementary volumes would require, in order to limit the pronounced curvatures, at wide and often unsightly intervals to be filled between the elementary diffusing volumes. All of the characteristics illustrated in FIG. 2, linked to the relative positions falling within FIG. 1, allow the construction of panels which are both transparent and illuminating, or translucent and illuminating. by assembling a mosaic of elementary volumes (elements-volume) whose intervals contain the bundles of optical fibers

  0 ensuring the supply of said volumes, embedded in the assembly material.

  Figure 4 represents the diffusing volume v, of: edge _ the positions of the fiber outlets such as 1 and 5 are those of FIG. 1. The positions such as 3 and 7 and mmne 2. 4, 6 and 8 with losses however , allow the projection of the exit surfaces of the fibers or bundles of fibers more or less punctually according to the distance between exit of fiber and diffusing surface, and according to the angle of incidence, but the glare is important for the boxes with

  running power lights. This device constitutes a means of drawing attention to the diffuser or a precise location thereof, with the possibility of playing on a change of color thanks to filters.

  The positions such as 2,4,6 and 8 allow in particular to logically design devices in which the diffusing volume can be moved away temporarily from the fiber outlet which feeds it. They may be mobile, pivoting or rotating volumes, of relatively small thickness, which regain their role as a diffuser at the outlet of optical fiber when they return to their initial type 1 position. This configuration is illustrated by the example of the window whose movable panel would diffuse light at night. FIG. 4 illustrates the synthesis of the possibilities of implementing the device in a necessarily flat pas20 panel, fed by a bundle of optical fibers at 1. The cross-hatched zones represent the filling material of the joints between the diffusing elementary volumes, filling interrupted in the drawing to leave 25L, see an example of beam position and its sub-beam. x optical fibers housed in the joints, without excessive bending. Volume 2, fed perpendicularly under the rear face, diffuses only over a restricted area -30 often dazzling at current powers. Volume 3 only becomes diffusing if it finds its

  position in the main plane of its housing. The fibers were voluntarily grouped in two ways for illu-, possibility of limiting the 35 pua iti ornament systems.

- 8 -

Claims (4)

  1) Device consisting of an optical fiber outlet and a diffusing volume, suitably positioned, or permanently assembled, and making it possible to transfer light or radiation close to the light spectrum, the optical fiber or the bundle of fibers combined to constitute one   conductor, towards the diffusing volume, ensuring desired effects without depriving other applications specific to transmission by optical fiber10).   2) Device according to claim 1 which allows, for a specific purpose, to optimize the diffusion of radiation in a non-spheroidal volume, a single volume or made up of a pre-wired assembly. 15 3) Device which according to claim 2 allows the outputs of optical fibers supplying several elementary volumes assembled in a mosaic around a single point when the angles of the element-volumes around this point are at most slightly greater than the angle of opening of the light beam coming from the optical fibers.  4) Device which according to claim 1, claim 2 or claim 3 allows, from elementary transparent or translucent volumes, to provide and produce assemblies or surfaces normally transparent, translucent or opaque, but which become illuminating or characteristic of the presence of a wavelength emitted, when the optical fiber or the network of fibers installed is connected to a light box producing radiations in the visible spectrum or around it. 5J Device which according to claim 1 and the reverndication 4 allows, i from transparent or translucent volumes, to predict and realize   elements likely to draw attention to a concentration of light and / or a change in color or light intensity from a remote light box.   - 9 6) Device which according to claim 1 and claim 5 allows to maintain the mobility of a diffusing surface while preserving a possibility in certain positions of reception and (5 of diffusion by this surface of a light radiation transmitted by a fiber excited optics   by a light box. 7) Device which according to any one of the preceding claims is characterized by a   1t0 appropriate positioning of the diffusing surface in relation to the optical fiber outlet, according to angular and distance parameters which can be specified experimentally in the final phase of production or installation without calling into question   the essential characteristics of the device.   8) Device which according to any one of   previous claims retains all   benefits of features and treatments   particular of the radiations used.