EP1203187B1 - Illuminating spotlight projector and lighting installation with offset light source - Google Patents

Abstract

The invention concerns an illuminating spotlight emitting a narrow beam. The spotlight has a highly concentrated light source and a concave reflector for emitting an illuminating beam in a specific direction, along an emitting axis. A converging lens is interposed between the source and the reflector and in a plane passing through a conical segment. The source is bordered laterally on the reflector side with a sector of the converging lens providing a virtual image of the source located beyond the emitting axis, on the side opposite that of the lens. The virtual image of the light source is formed at the focus of the conical segment locally defining the reflector.

Description

The present invention relates to a projector narrow beam emitting light, comprising a highly concentrated light source and a concave reflector to emit a lighting beam in one direction given, along an emission axis.

A lighting projector according to the preamble of claim 1 is known from GB-A-611 032.

The invention also relates to an installation lighting made with such a projector.

In many cases, it is interesting for control the distribution of lighting in a room or more generally on a site, to have a definition beam angular very precise. It means that the angle beam opening must be very small.

In general it is a light beam of rays in parallel theory, obtained by a parabolic reflector whose focus corresponds to the light source of the bulb and whose axis is the axis of emission. Such a projector is shown in part, in schematic section at the figure 1.

However, the emitted rays do not form a beam completely parallel because the light source is neither punctual nor monochrome.

Thus only the beams emitted by the source placed in focus F and falling on the reflector shown by the parabola segment UP that generates it are issued under shape of relatively parallel rays. All departments contained in the cone of axis XX and of half-angle δo / 2, FP generator passing through the reflector edge are emitted directly in the form of radial and non-parallel radii to the XX axis.

In practice, such a reflector is constituted by a paraboloid portion of revolution of axis XX, focal point F and defined by its parameter p, its opening radius R2 and its opening radius R1 rear (this rear opening serves for the passage of the lamp). The flux used increases when the radius R2 increases and it is considered that it is maximum when the characteristics of the reflector are such that: p = R 1 * R 2 / 2

The angle γ of the flux captured is delimited by the UP contour of the reflector. The development of a reflector more enveloping would lead to excessive dimensions. he should also be noted that lamps have significant dimensions relative to the reflector and the actual focus overflows necessarily from the theoretical focus what is the main cause of the lack of parallelism mentioned above. The divergence increases with the dimensions of the source or vice versa, if the focal length decreases and that the diameter of the reflector decreases compared to that from the source. We could consider placing a lens in front of the opening of the reflector but it would correct not only the direct flow but also the flow parallel rays reflected by the reflector.

In conclusion the correction that would give a such a lens placed in front would be inefficient.

Finally it should be noted that the effective angle emission of a beam is much higher than the assigned angle to a light source equipped with a reflector like for example halogen bulbs equipped directly a reflector. This angle is defined as the angle emission of 50% of the luminous flux, the rest of the flux being emitted in directions not contained in this cone resignation. The definition of the angle of illumination appears at FIG. 1A showing the separation curve of the light intensity according to the angle with respect to the XX axis (Fig. 1). This distribution is a bell curve and the angle of the projector is the one giving, by definition, intensity greater than the average half IM / 2 per ratio to the maximum intensity IM in the direction of the axis (α = o). This gives the angle α assigned to the beam, angle in which the flow should be maximum.

In practice this means that the beam is very imprecise.

The present invention aims to develop a projector to emit a very angle beam small and gathering almost all the luminous flux emitted by the source.

• la source est bordée latéralement du côté du réflecteur par un secteur de la lentille convergente donnant de la source une image virtuelle située au-delà de l'axe d'émission, de l'autre côté de celui de la lentille,
• l'image virtuelle de la source lumineuse étant formée au foyer du segment de conique définissant localement le réflecteur.

For this purpose the invention relates to a projector of the type defined above comprising
a convergent lens placed between the source and the reflector, and
in a plane passing through the axis of emission,
the concave reflector formed of a conical segment (ellipse or parabola), characterized in that, in said plane passing through the transmission axis,

• the source is bordered laterally on the reflector side by a sector of the convergent lens giving from the source a virtual image located beyond the emission axis, on the other side of that of the lens,
• the virtual image of the light source being formed at the focus of the conical segment locally defining the reflector.

Advantageously, the reflector has a structure of revolution around the axis of emission XX. next the case, the conic is a parabola whose axis is parallel to the transmission axis.

Thanks to the shift of the light source by its virtual image, one can have a parable sector of relatively large focal length, that is to say a parabolic area very enveloping.

It receives all the luminous flux transmitted by the peripheral lens. As this lens is itself very enveloping, a significant fraction of the emitted stream so goes through the lens to be reflected in form of almost parallel rays, by the reflector.

Only light rays emitted in the solid angle represented by the source and the rear edge of the lens are directed to the rear without being recovered. In general these rays bypass the optical system constituted through the peripheral lens and have a disordered orientation.

The corresponding part, frontal, for the solid angle defined by the front edge of the lens peripheral and whose summit is the light source, is issued directly.

According to an advantageous characteristic, the front opening of the peripheral lens is occupied by a lens whose focus corresponds to the light source so this lens emits a beam of radii parallel to the emission axis XX. This luminous flux is added to the luminous flux reflected by the reflector.

Thus almost all the luminous flux of the source is recovered in the form of a beam of rays parallel, that is to say in practice very weakly divergent. The solid emission angles γ and δ are fully controlled. Only the rear emission angle β corresponds to the flow of which part will be absorbed.

Advantageously, the peripheral lens and the front lens are made in one piece or constitute a single piece by assembling two lenses made separately. The reflector is preferably made of polished or polished aluminum metallized plastic vacuum, or glass with metallization reflective dichroic to titanium oxide by example.

According to another characteristic of the invention the reflector is generated by an ellipse arc whose second focus is on the transmission axis.

The invention also relates to an installation of lighting composed of a projector as defined above and at least one mirror forming a system lighting with remote focus, to illuminate an area lighting that the projector can not reach directly.

In these conditions the projector can be installed in an easily accessible place for interventions ; this area can also be accessed from make the existing power supply at the place where brought easily to this place, without the need for installation complicated in some cases of cables as for lighting with a direct projector.

Thanks to the very precise brush that forms the projector, it's easy to aim for a deflection mirror, even located at a relatively large distance from the projector without this leading to a significant loss of luminous flux passing by the mirror or without requiring a mirror important dimension. On the contrary, we can use small, lightweight, easy-to-use mirrors to realize and to install.

As the mirror is usually shot with its reflective side down, its reflective surface not likely to be cluttered with dust or deposits, so that its maintenance is practically nonexistent.

According to a particular characteristic interestingly, the mirror is formed of a reflector plate attached to a sleeve connected by a deformable rod to a foot.

According to another characteristic particularly interesting, the mirror is formed of a support bearing along its outer periphery a reflector held in its center by an adjustable screw connected to the support and regulating the curvature of the reflector.

• la figure 1 est un schéma de principe d'un projecteur à réflecteur parabolique connu,
• la figure 1A est une courbe donnant la répartition de l'intensité lumineuse d'un projecteur connu selon la figure 1,
• la figure 2 est un schéma de principe d'un projecteur selon l'invention,
• la figure 3 est une vue plus complète d'un exemple de réalisation de projecteur, au niveau des lentilles,
• la figure 4 est un schéma d'ensemble d'un projecteur,
• la figure 5 est une vue en coupe axiale d'un premier élément du projecteur,
• la figure 6 est une vue en coupe axiale de l'élément de projecteur muni de sa douille,
• la figure 7 est un schéma d'installation d'éclairage à foyer déporté selon un premier mode de réalisation,
• la figure 8 est un schéma d'une installation d'éclairage à plusieurs projecteurs déportés et plusieurs miroirs selon l'invention,
• les figures 9, 9A, 10, 10A sont respectivement des vues de côté et de détail, agrandies, de deux modes de réalisation de miroirs selon l'invention,
• la figure 11 montre un détail d'une fixation de miroir,
• la figure 12 est une vue de face d'un miroir selon l'invention,
• les figures 13 et 14 sont des vues en coupe de deux autres types de miroirs selon l'invention,
• la figure 15 est une vue en coupe d'un miroir à courbure réglable,
• la figure 16 montre un équipement à plusieurs miroirs,
• la figure 17 montre plusieurs formes de miroir,
• la figure 18 est une vue schématique de plusieurs miroirs alimentés par un seul projecteur,
• la figure 19 montre un ensemble de plusieurs miroirs,
• la figure 20 est une vue en perspective d'un miroir simple de forme rectangulaire,
• la figure 21 est une vue en perspective d'un miroir simple de forme octogonale,
• la figure 22 est une vue en coupe de l'installation d'un miroir selon les figures 20 ou 21,
• la figure 23 est une vue en coupe de l'installation de plusieurs miroirs du type de ceux des figures 20 et 21.

The present invention will be described hereinafter in more detail with the aid of the accompanying drawings in which:

• FIG. 1 is a block diagram of a known parabolic reflector projector,
• FIG. 1A is a curve giving the distribution of the luminous intensity of a known projector according to FIG. 1,
• FIG. 2 is a block diagram of a projector according to the invention,
• FIG. 3 is a more complete view of an exemplary embodiment of a projector, at the level of the lenses,
• FIG. 4 is an overall diagram of a projector,
• FIG. 5 is a view in axial section of a first element of the projector,
• FIG. 6 is a view in axial section of the projector element provided with its socket,
• FIG. 7 is a remote-focus lighting installation diagram according to a first embodiment,
• FIG. 8 is a diagram of a lighting installation with several remote projectors and several mirrors according to the invention,
• FIGS. 9, 9A, 10, 10A are respectively enlarged side and detail views of two embodiments of mirrors according to the invention,
• FIG. 11 shows a detail of a mirror attachment,
• FIG. 12 is a front view of a mirror according to the invention,
• Figures 13 and 14 are sectional views of two other types of mirrors according to the invention,
• FIG. 15 is a sectional view of a mirror with adjustable curvature,
• Figure 16 shows equipment with several mirrors,
• Figure 17 shows several forms of mirror,
• FIG. 18 is a schematic view of several mirrors powered by a single projector,
• Figure 19 shows a set of several mirrors,
• FIG. 20 is a perspective view of a simple mirror of rectangular shape,
• FIG. 21 is a perspective view of a simple mirror of octagonal shape,
• FIG. 22 is a sectional view of the installation of a mirror according to FIG. 20 or 21,
• Figure 23 is a sectional view of the installation of several mirrors of the type of those of Figures 20 and 21.

A projector according to the invention will be described below using the diagram in Figure 2.

The projector is intended to emit a beam narrow. It comprises a light source S housed in a bulb not shown and considered a source practically punctual.

This source S, placed on the transmission axis XX, that is to say, the axis along which we want to direct the beam, emits in the solid angle that surrounds it.

To simplify the drawing and explanations, FIG. 2 represents only part of an axial section or supposed to be such of the projector by a plane passing through the transmission axis XX.

Source S is bordered on one side of the half-plane delimited by the transmission axis XX, by a convergent lens LA, represented only by its section. This lens has a focal length greater than the distance (d) separating from the source S to give this source S a virtual image S 'located in the half-plane other than that of the lens LA, with respect to the transmission axis XX.

Beyond the LA lens is a reflector concave RF defined by a conical segment (ab) whose one or the focus F coincides with the virtual image S 'of the light source S. The length of the segment (ab) is chosen to cover the entire beam emitted by the source S and having crossed the LA lens.

According to the properties of the conics, the radii r1, r2 and all the intermediate radii, reflected by the RF reflector and coming from the source S, are directed towards the second focus of the conic which may be the second focal point of the ellipse placed on the transmission axis XX or the focus rejected at infinity in the direction of the transmission axis XX if the conical sector (ab) belongs to a parabola of axis X ₁ X ₁ and focus F.

To also recover the rays emitted by the solid angle δ corresponding to the cone resting on the LA1 edge of the LA lens and whose top is the source S, there is provided a convergent lenticular lens LF, placed against the LA1 edge of the LA lens and whose focus coincides with source S. This LF lens will then emit radii r3, r4 parallel to the axis XX.

Thus all the rays emitted by the source S in the peripheral angle γ and the frontal angle δ will be transformed in parallel or substantially parallel radii the XX axis.

In general, the lens LA, a segment of which is represented in FIG. 2 in the form of a section of the lens by a plane bearing on the axis XX, is a lens of revolution of axis XX. Under these conditions the conical sector (ab) also defines a surface generated by the rotation of the segment (ab) about the axis XX (and not the axis X ₁ X ₁ ). It is not in these conditions of a paraboloid but of a pseudo-paraboloid.

Figure 3 is a schematic view of a projector according to the invention showing the monobloc form of a combined lens 1 grouping the annular lens LA and the front lens LF.

Only the filament constituting the source S of the bulb has been represented. This figure also shows the reflector 3 and the sketch of the envelope 6 of the projector.

This figure corresponds to a projector having a form of revolution around the axis of emission XX. The different emission angles γ, δ have been represented as well that the emission angle backward β.

FIG. 4 is a view in axial section of a practical embodiment of a projector according to the invention comprising a lens 1 housing a bulb halogen 2 inside the reflector 3 worn by a ring 31 provided with elastic tabs 32 coming into the annular groove 11 of the lens 1. The reflector 3 is also attached to the ring 31 by its bottom folded 33, possibly crimped in a peripheral ring 34 (FIG. 5) in a peripheral groove 35 of the ring 31. The assembly formed by the lens 1, the bulb 2 and the reflector 3 constitutes a product manufactured as such and not removable.

Figure 4 also shows the particular shape of the front lens made up of a part annular 12 and an axial portion 13 so as to spare a housing 14 receiving the tip 21 of the bulb 2 for the where the lens is separated from the bulb constituting the lamp, the body of the bulb being itself housed in the cavity 15 defined mainly by the inner contour of the annular lens. The whole thus realized can be completed at the back by a centering sleeve 40 in which come the pins 22 of the bulb 2. This socket is itself integrated into a sealing 41 traversed by the contact pins 42. These contact pins are intended to fit in the block contact 5 itself connected to the power supply.

The set described above is housed in a housing 6 of the projector connected in a steerable manner to a foot 7; the locking in rotation is done with a screw 61 resting against the outer contour of the tip 71 of the 7. Other means of installing the projector are not represented.

Figure 5 shows the subset formed of the lens 1, bulb 2, reflector 3 and ring 31.

Figure 6 shows the complete subset formed of a subset similar to that of Figure 5, completed by the socket 40, and the base 41 with the pins 42 that exceed.

Figure 7 shows schematically a first example of realization of a lighting installation in light source (or light source) deportees according to the invention. This installation is intended to illuminate a object or an SE surface in a very limited and precise way. For this we install a projector P constituting the luminous focus according to the invention near a source A power supply at a height H, easily accessible. The installation also includes a mirror M, steerable, to which is directed the angle beam F α; the appropriately oriented mirror returns a angle beam α1 to illuminate the surface SE. The angle α1 is equal to the angle α if the mirror M is plane. Otherwise, this angle is different. It can be superior or less than the angle α following the curvature of the mirror M.

Figure 8 is a plan view of an installation to several P1-P6 projectors and several associated mirrors M1-M6, a mirror being associated with each projector. The beams reflected by the M1-M6 mirrors carry the references α1-α6.

This figure shows one of the advantages of remote source lighting installation (s) according to the invention because it allows to group the projectors for example in two groups, one with the P1 projectors, P2, P3, the other with projectors P4, P5, P6. Mirrors may be placed anywhere space, so as to be as discreet as possible and allow the best lighting of the surface to be illuminated; the latter is not shown in this figure. This surface to be illuminated may be composed of several elements illuminated each separately by a mirror.

As will be seen below, the important thing for the mirrors is that these are also light, discreet and orientable as possible to allow them to be installed simply and discreetly in the most appropriate.

Different examples of mirrors will be described below.

Thus, FIGS. 9, 9A show a first embodiment of a mirror 100 formed of a convex reflecting surface 101, fixed at its center to a sleeve 102 by a screw 103. This sleeve is itself fixed to a deformable rod 104 carried by a tube 105 fixed to a foot 106. The foot 106 comprises for example, on its rear face, a mechanical fastener 107 or two adhesive plates 108 as shown in Figure 11. The connection between the sleeve 102 and the deformable rod 104 is made for example using a screw 109 carried by an operating rod 110. The screw 109 compresses the end of the rod 104 which can be a rigid electric cable to a driver, for example section 1.5 mm ² or 2.5 mm ² , which has the advantage of being deformable very easily and retain the deformation.

The reflecting surface 101 of the mirror is using the rod 110 that is held by hand and that it is maneuvered to direct the reflected light beam.

Figure 9A shows the detail of the assembly between the sleeve 102, the reflector 101 with the central screw 103, the end of the rod 104 and the screw 109 worn by the end of the operating rod 110. In this mode of realization the end of the rod 104 is introduced transversely in the housing of the sleeve 102 and the screw 109 is screwed in the axial direction.

The mirror variant 200 according to FIG. 10 corresponds essentially to the embodiment of the figures 9, 9A except that the deformable rod 204 arrives in the axis in the sleeve 202 and the screw 209 is screwed radially. The other constituent elements of this mirror are analogous, even identical to those of the mirror 100 and carry the same references increased by 100.

Unlike the mirror 100, the mirror 200 does not has no tube 105 and the stem, flexible or deformable 204, connects the sleeve 202 to the plate 206. fixing 205 of the deformable rod 204 on the plate 206 may have a construction similar to Exhibit 202. This piece 205 can be attached from the back using a screw to the plate 206 and the rod 204 can be attached to it as in the sleeve 202 by a screw not shown.

The fixing means of the plate 206 on the support (wall, ceiling or object) are the same as those of the plate 106 shown in FIG.

Figure 12 shows a front view of a mirror 250 with a non-regular 251 contour surrounding the surface 252 of the reflector. The reflector carries a central fastener 253 screw-shaped. The irregular outline 251 is intended to mask the mirror or to integrate it into a set.

Figure 13 is a sectional view of a mirror 260 of which only the support 261, which carries the reflector 262 in the form of a sandwich structure, is shown as that the deformable rod 263 of orientation of the mirror.

Figure 14 shows, in sectional view, another mirror form 270 with a sleeve-shaped support 271 connected to the deformable support rod 273. The reflector proper 272 is surrounded by a frame, for example a U-shaped profile, 274.

Figure 15 shows a mirror 280, curvature adjustable. This mirror consists of a sleeve 281 carrying a support 282 forming the reflector frame and carrying, the along the outer periphery, the reflector 283. In its center, the reflector 283 is held by a screw 284 housed in a thread of the sleeve 281. By tightening more or less the screw, we bend more or less the reflective surface 283 from the flat or almost planar shape shown in broken line. Sleeve 281 is also worn by a deformable rod 285.

Figure 16 shows equipment made of three mirrors 290, 291, 292 for three projectors separate or to receive the single beam of the same projector but to deflect beam portions in different directions. These reflectors 290, 291, 292 are connected by rods 293, 294, 295, deformable, to a plate of common support 296 provided with non-fastening means represented.

Figure 17 shows three shapes of reflectors 300, 301, 302, respectively circular, rectangular to rounded and octagonal corners. These reflectors can equip the mirrors described previously.

Figure 18 shows a set of three mirrors 350, 351, 352 receiving a common beam to send back this beam partially in three directions different as represented by broken lines. These mirrors 350, 351, 352 are carried by rods deformable 353, 354, 355 on a bent support 356 attached to a curved support such as a partition 357. Such an installation can be done in any orientation on a support 357 vertical, horizontal, or inclined.

Figure 19 shows a support rail 360 carrying four mirrors 361, 362, 363, 364 adjustably fixed to the rail, itself provided with fastening means 365, 366. The rail 360 may be a simple straight rod or a frame 367 like the one shown in complete line interrupted.

Figure 20 shows in perspective view a particularly interesting embodiment of a mirror 400 formed of a reflector 401 and a support 402 connected to the reflector by a branch 403. The assembly can be cut into a sheet of metal and folded as shown.

The folded parts are not rigid, it is possible to deform the link 403 once the leg 402 attached to the appropriate place, to orient the reflector 401 as desired.

Figure 21 shows a similar reflector 410 to the reflector 400 of Figure 20 except that it has a shape octagonal and not rectangular.

FIG. 22 is a sectional view of the reflector 400 showing attachment to a support 404.

Fig. 23 is a schematic side view of a set of three reflectors 420, 421, 422, of the type of that of Figure 20, attached to a common support 423 itself attached to a ceiling, wall, or other 424.

According to a variant not shown, the lenses of the projector are partly or wholly lenses of Fresnel.

Claims (10)

1. Spotlight emitting a narrow beam comprising a very concentrated light source (S), a concave reflector (RF) to emit a lighting beam in a given direction, along an emission axis (XX), the said reflector being defined locally by a segment of a conic section (ab) in a plane (P) passing through the emission axis (XX), and a convergent lens (LA) positioned between the source (S) and the reflector (RF), characterised by the fact that:

   in the said plane (P) passing through the emission axis (XX):

   the source (S) is bordered laterally on the reflector side by a sector of the convergent lens (LA) giving a virtual image (S') of the source (S), situated beyond the emission axis (XX), on the other side from that of the lens (LA),

   the virtual image (S') of the light source (S) being formed at the focus (F) of the segment of conic section (ab) locally defining the reflector (RF).
2. Spotlight as described in claim 1,
   characterised by the fact that
   it has a structure of revolution about the emission axis (XX) .
3. Spotlight as described in claim 1,
   characterised by the fact that
   the conic section (ab) is an ellipse, the second focus of which is situated on the emission axis.
4. Spotlight as described in claim 1,
   characterised by the fact that
   the conic section (ab) is a parabola, the axis (X₁X₁) of which is parallel with the emission axis (XX).
5. Spotlight as described in claim 2,
   characterised by the fact that
   the frontal opening left by the lens of revolution (LA) about the emission axis (XX) is occupied by a convergent lens (LF), the focal point of which corresponds to the light source (S).
6. Spotlight as described in claims 2 and 5,
   characterised by the fact that
   the lens (LA, LF) is in one piece and houses the lamp (2) forming the light source (S).
7. Spotlight as described in claim 1,
   characterised by the fact that
   the angle of cover (γ) of the peripheral lens (LA) corresponds to the length of the segment of conic section (ab) defining the reflector (RF).
8. Lighting apparatus with offset focal point of light,
   characterised by

   a spotlight (P) as described in one of claims 1 to 7,

   at least one mirror (M) positioned on the emission axis and directing the light to the surface to be illuminated (SE).
9. Lighting apparatus as described in claim 8, characterised by the fact that
   the mirror (100) is formed of a plate (101) forming a reflector fixed to a sleeve (102) connected by a deformable rod (104) to a foot (106).
10. Lighting apparatus as described in claim 8,
    characterised by the fact that
    the mirror (280) is formed of a support (282) carrying along its external periphery a reflector (283) held at its centre by an adjustable screw (284) connected to the support and adjusting the curvature of the reflector (283).

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