EP0208569A1 - Lighting fixture, especially a stage light projector provided with means for simultaneously adjusting all the projector's parameters - Google Patents

Abstract

A lighting device comprises a light source adapted to produce a light beam. A reflective mirror is disposed behind the light source. The device also comprises a plurality of optical lenses and a plurality of colored filters. The light source comprises at least one filament and has at least one dimension greater than six millimeters in the direction in which the filament is disposed. The colored filters are movable and adapted to be inserted totally or partly into the path of the light beam. They are disposed on the opposite side of the plurality of optical lenses to the light source. An adjustable iris diaphragm is inserted between certain lenses of the plurality of lenses, on the path of the light beam.

Description

The present invention relates to a lighting device, capable of producing a halo of light colored in a homogeneous manner and adjustable both in intensity and in color.

A particularly advantageous application of this type of device is that of scenic lighting, although, in general, any situation in which colored lighting is used may constitute an application of the present invention.

For example, the lights for cinematographic or photographic shots can also constitute an application of the invention.

It is known, when it is desired to illuminate a determined area, by coloring it at the same time in a determined manner, to illuminate this area using several combined light sources.

More precisely, obtaining a particular coloration in a localized halo of light, combined with a determined light intensity, is usually done by bringing together on this halo several light beams uniformly colored each in a fundamental color, allowing, by appropriate dosage of these fundamental colors to obtain the desired shade of color.

Usually also, the relative dosage of the fundamental colors is done by the individual adjustment of the light intensity of each of the sources.

To this relative adjustment of the intensity of the sources is added a global dosage of the light intensity, in order to obtain, in addition to the desired color, the intensity of lighting desired in the halo.

Furthermore, these light sources, usually projectors, are spaced from each other, and are individually set.

• Soit les opérateurs doivent être nombreux et habiles à diriger les sources différentes simultanément vers le même sujet à éclairer, et à régler l'intensité lumineuse de chaque projecteur à la fois en fonction de la couleur recherchée et de l'intensité lumineuse globale recherchée ;

This has many drawbacks:

• Either the operators must be numerous and skilled in directing different sources simultaneously towards the same subject to be illuminated, and in adjusting the light intensity of each projector both according to the color sought and the overall light intensity sought;

Either the projectors are controlled remotely, using motors, electric for example, and the installation of such controls making it possible to adjust both their orientation and their light intensity is complex and expensive.

Furthermore, the occurrence of the need to obtain several halos of light simultaneously in different places is frequent.

In addition, the subjects to be lit are often mobile. They should therefore be followed by a simultaneous and appropriate orientation of the projectors. As these projectors are not placed in the same place, for reasons of space and mobility, the fact of following a mobile subject is a relatively complex task, especially when implementing a simultaneous remote control.

• Chaque projecteur crée un halo, généralement sensiblement ovale du fait de l'obliquité du faisceau par rapport au plan dans lequel se meut le sujet, et, pour les raisons énoncées ci-dessus, les halos ne peuvent se superposer exactement.

In practice, the angles of incidence relative to the subject of the projectors whose beams are combined, in order to provide the resulting halo with the desired coloration, are sufficiently different to create a non-homogeneous halo:

• Each spotlight creates a halo, generally substantially oval due to the obliquity of the beam relative to the plane in which the subject moves, and, for the reasons stated above, the halos cannot be exactly superimposed.

The most advantageous solution for solving such a problem consists in producing the desired mixture of colors in a single projector, or, more generally, on the propagation path of a light beam.

Such a solution has already been envisaged and described by the applicant in patent application FR 8308201.

There is provided a projector comprising a light source, means giving this light source a defined direction of propagation, thereby determining a beam, and means for adjusting the width, intensity and coloring of the beam.

More precisely, the coloring of the beam is done by interposition on the path of the latter of a plurality of colored filters, comprising in this case sheets of colored transparent material, known in the art under the name of "gelatins" , each colored filter being interposed over a more or less significant part of the surface of the cross section of the beam at the level of this filter.

Thus, according to the proportion of coloring surface interposed in the light beam by each filter relative to the overall surface of the section of said beam at the level of this filter, a density of coloration in the color of this appropriate filter is obtained, depending on the setting. performed.

In practice, it has been found necessary to make each filter in two moving parts in a plane normal to the light beam, the two parts of each filter being able to completely meet in an extreme position, or on the contrary, take all the intermediate positions up to 'to the other extreme position where they are separated so as no longer to interpose in the light beam.

Although constituting a significant progress compared to the prior art, the embodiments originating from this patent produce colored luminous halos which lack homogeneity.

This is explained by the fact that, when a filter partially colors the light beam, interposing on a defined part of the surface of its cross section at its level, it precisely colors a part of this surface.

This amounts to saying that part of the surface of this section is completely colored by the filter, while a remaining part of this surface is absolutely not colored by this filter.

For example, if we color 40% of the surface of the beam only in red, 40% of the surface of the beam will be completely red, and the rest, completely white.

This is found on the luminous halo illuminating the subject. However, this is not the goal.

What we are looking for, in the specific case of the example mentioned above, is a globally colored halo with 40% red over its entire surface, and in a homogeneous manner.

The object of the present invention is to allow the homogeneous coloring of a halo of light coming from a lighting device, said halo being colored according to the shade sought, said shade being adjustable at will.

• a) la source lumineuse, dite large, présente au moins une dimension supérieure à 6 mm dans le sens de laquelle se trouve disposé au moins un filament,
• b) les filtres colorés sont mobiles et aptes à s'interposer totalement ou partiellement sur le trajet du faisceau lumineux émis par la source,
• c) les filtres colorés sont disposés en aval de la pluralité de lentilles optiques par rapport à la source et,
• d) un diaphragme de mise au point, du genre à iris d'ouverture réglable, est interposé entre des lentilles constituant ladite pluralité de lentilles, sur le trajet du faisceau lumineux.

Surprisingly, the applicant has found that a lighting device as described below makes it possible to obtain this result. Such a device is of the type comprising a light source, a reflective mirror disposed behind it, a plurality of optical lenses, and a plurality of colored filters, characterized in that:

• a) the so-called wide light source has at least one dimension greater than 6 mm in the direction of which at least one filament is placed,
• b) the colored filters are mobile and capable of interposing totally or partially on the path of the light beam emitted by the source,
• c) the color filters are arranged downstream of the plurality of optical lenses with respect to the source and,
• d) a focusing diaphragm, of the type with an iris of adjustable aperture, is interposed between lenses constituting said plurality of lenses, on the path of the light bleam.

In addition, advantageously, such a device is also characterized in that the lens closest to said wide source, immediately downstream thereof, is a so-called aspherical lens, of substantially conical shape with widely rounded tip, and one of which flat base is normal to the direction of propagation of the light beam and is oriented towards the source.

The arrangement of the filters downstream of the optical lenses would suggest, according to the embodiments of the prior art, of obtaining a partially colored beam, in a non-homogeneous manner.

However, in practice, the beam, and by the same token the halo of light obtained with a device according to the invention, is colored uniformly.

Advantageously, a device according to the invention also comprises at least two lenses arranged downstream of said diaphragm, at least one of said two lenses of the plurality of lenses is axially movable, in the direction of propagation of the light beam, and a shutter means adjustable, opaque, consisting of two opaque plates, movable in a plane normal to the path of the light beam, can partially interpose on this path.

Such arrangements allow adjustments to be made to the focus, the width of the light beam and the light intensity.

Advantageously, the colored filters are each a pair of sheets of colored transparent material, called gelatins, which are each stretched respectively on a metal frame arranged in a plane normal to the path of the light beam, these frames being mobile in this plane so as to be able to get closer or move away and thus partially or totally interpose said gelatins on the path of the light beam.

Preferably, a device according to the invention comprises a shutter means, three colored filters, and a non-colored filter capable of making the more or less blurred the light bleam.

Thus, it is possible to adjust the device according to the invention so as to obtain a uniform light beam adjustable in width, intensity, coloring, and definition (as opposed to "blur"), that is to say according to the whole. parameters that we can consider adjusting.

Such a device, implemented in a projector, for example, therefore makes it possible, by the range of possibilities it offers, to considerably reduce the number of projectors to be used, and to improve the quality of the light halo without any other disadvantage .

The number of possible settings, however, leads to a certain complexity of manipulation, which can advantageously be resolved by the use of commands that can be programmed.

• la figure 1 est une représentation schématique en coupe longitudinale d'un mode de réalisation de l'invention;
• la figure 2 est une représentation schématique en perspective du mode de réalisation de l'invention représentée à la figure 1 ;
• la figure 3 est une représentation schématique en coupe longitudinale d'une variante d'exécution de l'invention ;
• la figure 4 est une représentation schématique en perspective, avec un élément présentant une portion arrachée, de la variante d'exécution de l'invention représentée à la figure 3.

The advantages and characteristics of the invention will also emerge from the detailed description which follows, with reference to the appended drawings in which:

• Figure 1 is a schematic representation in longitudinal section of an embodiment of the invention;
• Figure 2 is a schematic perspective representation of the embodiment of the invention shown in Figure 1;
• Figure 3 is a schematic representation in longitudinal section of an alternative embodiment of the invention;
• FIG. 4 is a schematic perspective representation, with an element having a cutaway portion, of the alternative embodiment of the invention shown in FIG. 3.

In more detail, with reference to FIGS. 1 and 2, a projector 1 implementing a method according to a first embodiment of the invention described by way of example comprises a so-called wide light source 10 consisting of a bulb glass 13 substantially ovoid, the axis of which is arranged generally perpendicular to the general axis of the projector 1. Typically, such a bulb has an axial width of the order of 30 mm, and a circular cross section with a diameter of 25 mm.

Two electrodes 11, 12 made up of filaments extend parallel to the axis of the bulb 13 inside of it.

The axial dimension of these two electrodes, which constitute the light source proper, is greater than 6 mm.

Typically, it is 13 mm.

Such an axial dimension in practice determines the width of the light source. This is not, in this case, negligible compared to the dimensions of the different optical elements used in the invention and described below, the light source is said to be "wide".

Advantageously, the bulb contains a halogen gas.

Relative to the assembly of the headlamp 1, the source 10 is located near one of the closed ends thereof, the so-called upstream end.

The opposite open end through which the light beam exits is said to be downstream.

On the axis of the headlamp 1, immediately upstream from the source 10, is arranged a substantially hemispherical reflector 14.

The pole of this hemisphere is arranged in the axis of the projector, oriented upstream. In this way, the reflector 14 reflects the light radiation coming from the source 10 generally downstream.

Downstream of the source 10, coaxially with the projector, is arranged a lens 15, called aspherical. Such a lens has a substantially frustoconical shape, the base of which would be normal to the axis of the headlamp 1 and the point of which, broadly rounded, would face downstream of said headlamp.

Further downstream, coaxial with the axis of the headlight 1, is arranged an annular diaphragm 16 of the iris type, having an annular opening 17 of adjustable diameter. using appropriate adjustment means (not shown).

Such a diaphragm, similar to those commonly used in cameras, is known per se.

Downstream of the diaphragm 16 is arranged, coaxially, a first lens 18.

Such a lens, in the embodiment described, is generally convex, asymmetrical axially, and has a substantially planar face, upstream, and a convex face, substantially in the form of a portion of a sphere, facing downstream.

A second lens 19, of a kind similar to the first, is arranged coaxially downstream of the latter at a distance adjustable by axial displacement of at least one of the two lenses 18,19.

In practice, these two lenses are axially movable and can be operated by suitable means known per se (not shown).

According to the embodiment described by way of example, the second lens 19 has a general diameter greater than that of the first, is also convex, asymmetrical axially, and has a substantially flat face turned upstream.

A mirror image 51, 52 of the electrodes 11, 12 is formed at the level of the lens 19.

Between the lenses 18 and 19 is disposed, in a plane normal to the axis of the projector, a shutter means, or shutter 20. Advantageously, this shutter 20 is arranged substantially at mid-axial distance between the two lenses 18,19 .

This shutter 20 consists of two rectangular plates 21, opaque, metallic for example, rigidly mounted on supports 22 capable of sliding on a slide 23, for example formed of two parallel rails.

The slide 23 is arranged in a direction perpendicular to the axis of the projector, slightly away of this axis.

In practice, the axis of the projector cuts the median of the plates 21 parallel to the slide 23.

• - une première position dans laquelle les plaques 21 se joignent bord à bord, adjacentes dans leur plan, et
• - une deuxième position dans laquelle les plaques 21 présentent un écartement 45 maximal déterminé par le débattement des supports 22 autorisé par les butées 24 lorsqu'ils coulissent sur la glissière 23.

Two stops 24 located at the two ends of the slide determine a movement of the supports 22 between two extreme positions, namely:

• a first position in which the plates 21 join edge to edge, adjacent in their plane, and
• a second position in which the plates 21 have a maximum spacing 45 determined by the movement of the supports 22 authorized by the stops 24 when they slide on the slide 23.

Downstream of the lens 19 are arranged substantially along planes normal to the axis of the headlight, and in succession, axially equidistant, four filters 25.25 ', 25 ", 25"'.

In order to simplify the reading of the present description, only one of these filters will be described, namely the filter 25, it being understood that, apart from the color and / or the nature of the surface of a filter element, all of these filters are strictly identical.

The identical elements described carry, from one filter to another, the same reference numerals to which the symbols (, ', ","') are added to identify their belonging to the filters carrying the same symbols respectively.

The filter 25 comprises two U-shaped frames 26,27, asymmetrical in that one of the branches of the U is larger than the other, these two frames being identical, arranged head to tail in two parallel planes very slightly apart to allow these two frames to partially overlap with negligible play.

The two frames 26, 27 are in fact substantially arranged facing each other, so that, when they are partially superimposed, the ends of the branches of the frame 26 partially cover the ends of the two branches of the frame 27, the frame 26 being disposed the further downstream.

The frames 26 and 27 are respectively mounted on supports 28 and 29, capable of sliding on a slide 30. This slide 30, similar to the slide 23 of the shutter, is, for example, made up of two parallel rails.

In the described embodiments of the present invention, the slide 30 is, in the general plane of the filter 25, normal to the axis of the projector, perpendicular to the direction of the slide 23.

This direction can be defined as being horizontal, the slide 23 being vertical, this being of course relative to the direction of the headlight axis which is, in this case, horizontal.

It is however possible, in other embodiments, to orient these slides differently.

Two stops 31 are arranged at each end of the slide 30, in order to limit the movement of the supports 28, 29.

Such a clearance thus determines the displacement of the frames, which can be separated from one another, or, on the contrary, brought together until a slight overlapping of the ends of their branches, overlapping limited by the abutment of the two supports 28.29 against each other.

On the frames 26 and 27 are stretched filter elements made of transparent sheets, commonly called gelatins, respectively 32 and 33.

These gelatins have a rectangular trapezoid shape, so as to cooperate with the unequal branches of the U formed by each of the frames, and are, like these frames, arranged head to tail so that their biased edges 34, only edges not integral with the frames, are parallel.

When the supports 28 and 29 are separated against the stops 31, the edges 34 are also separated, and the space 35 separating them is crossed in the middle by the axis of the projector. The filter 25 is then in the so-called open position. When the supports 28 and 29 are in abutment against each other, the gelatins 32 and 33 reopen in partial superimposition in a determined narrow band, brought in a single plane, by an edge 34 and the projection in an axial direction on the other edge 34 in the same plane.

This superimposition is made as narrow as possible, and in fact serves as a safety margin to ensure that when the filter 25 is in this position, called closed, the gelatins 32 and 33 are necessarily crossed by the axis of the projector.

Gelatins 32 and 33 are of the same nature and the same color.

In the embodiments described, the gelatin filters 25, 25 'and 25 "have a smooth surface and are of three different colors, preferably complementary.

The gelatins 32 "and 33", of the filter 25 ", are, on the other hand, colorless and of grainy surface, such gelatins being able to blur the outline of a light beam which passes through them.

The supports 22 of the shutter, the supports 28 and 29 and their correspondents of the other filters, are controlled in their deflections on their respective slides by suitable control means, advantageously servo motors with programmable control. Such means are not shown in the figures.

Figures 3 and 4 show an alternative embodiment of the invention, in which the elements already described in the first embodiment bear the same reference numerals.

From upstream to downstream, there is a hemispherical reflector 14, a wide source 10, and an aspherical lens 15.

A second lens 36, of convex asymmetrical shape, is arranged coxially downstream of the lens aspherical 15.

We then find the iris diaphragm with adjustable opening 17.

Downstream, coaxially with these elements, there is an optical focusing device 37.

Such a device comprises a substantially cylindrical body, a first set of lenses mounted coaxially in succession 39,41, and a second set of lenses 42,43 also mounted coaxial in succession, the second set being axially movable relative to the first.

An annular support ring 44, extending radially from the cylindrical body 38, makes it possible to subject the device 37 to the projector.

A mirror image 51, 52 of the electrodes 11, 12 is formed at the level of the lens 43.

Such a device, known per se, is commonly called "ZOOM" and is in widespread use in photography as in stage lighting.

In this embodiment of the invention, the shutter 20 is located downstream of the "ZOOM" 37, immediately upstream of the cascade of filters 25,25 ', 25 "and 25"'.

The shutter 20 and the filters 25.25 ', 25 "and 25"' are identical to those used in the first embodiment described.

In the embodiments of the invention described, the reflector 14 partly reflects the light radiation emitted by the wide source 10 downstream, another part of this radiation going directly in this direction.

In fact, the role of the reflector 14 is to allow all of the radiation to go downstream from the projector.

In practice, the axis of the projector is the general direction of propagation of light radiation, which thus forms a beam.

The light beam passes through the diaphragm 16 which determines, by its opening 17, and in a proportional manner, the diameter of this beam a liver out of the projector.

The axially movable lenses 18, 19, in the first embodiment, or the "zoom" 37, in the second embodiment of the invention, are used to focus the image, here a simple circle whose sharpness is defined by the outline.

To obtain the desired homogeneous color mixture, it is preferable to carry out a correct focusing, producing a clearly delimited light beam.

The shutter 20, located either between the lenses 18,19, or downstream of the "ZOOM" 37, has the function of adjusting the light intensity.

When this shutter is in the open position, the spacing 45 between the plates 21 is wide enough to allow the entire light beam to pass.

The 25.25 ′ and 25 ″ filters more or less color this light beam downstream of the shutter, the gelatins being capable of deviating sufficiently when the filter is in the open position so as not to be in the path of this beam .

The blurring which can be sought for certain particular applications must not, if a homogeneous mixture of colors is to be obtained, result from a focusing defect.

The 25 "filter, fitted with granular surface gelatins, makes it possible to obtain a blurred contour beam from a correctly developed beam.

The blurred nature of the beam, and consequently of the halo which it projects, can be a desired effect in certain productions.

In all cases, it has been observed that, once the development has been carried out, the mixture of colors obtained in the luminous halo is homogeneous, despite the arrangement of the colored filters downstream of the elements ensuring the development, thanks to the specific provisions of the invention.

It is, of course, up to the person skilled in the art to make improvements, adaptations or other embodiments to the present invention, in particular as regards the various optical elements, which do not constitute the essence of the invention.

More generally, the embodiments described above constitute only non-limiting examples of implementation of the means constituting the present invention.

Claims (15)

1) Lighting device of the kind comprising a light source, a reflective mirror disposed behind it, a plurality of optical lenses, and a plurality of color filters, characterized in that: a) The light source (10), called wide, has at least one dimension greater than 6mm in the direction of which at least one filament is placed, b) The colored filters (25,25 ′, 25 ′) are mobile and capable of interposing totally or partially on the path of the light beam emitted by the source, c) The color filters (25.25 ', 25 ") are arranged downstream of the plurality of optical lenses with respect to the source and, d) A focusing diaphragm (16), of the type with adjustable aperture iris, is interposed between lenses constituting said plurality of lenses, on the path of the light beam. 2) A lighting device according to claim 1, characterized in that the lens closest to said wide source, immediately downstream thereof, is a so-called aspherical lens (15), of substantially conical shape with widely rounded tip, and of which a flat base is normal to the direction of propagation of the light beam and is oriented towards the source. 3) Lighting device according to any one of the preceding claims, characterized in that at least two lenses are arranged downstream of said diaphragm. 4) Device according to claim 3, characterized in that at least one of said two lenses of the plurality of lenses is axially movable, in the direction of propagation of the light beam. 5) Lighting device according to any one of the preceding claims, characterized in that it comprises at least one shutter hub (20) adjustable, opaque, of the light beam intended to regulate the light intensity thereof . 6) A lighting device according to claim 5, characterized in that said shutter means (20) consists of two opaque plates (21) movable in a plane normal to the path of the light beam can be interposed partially or completely on this path, said plates being provided with means capable of making it slide on a support defining the direction of their mobility. 7) Lighting device according to any one of the preceding claims, characterized in that said colored filters (25.25 ', 25 ") are each a pair of sheets of colored transparent material, called gelatins (32.32', 32 ", 33.33 ', 33"), which are each stretched respectively on a metal frame (26.26', 26 ", 27.27 ', 27") arranged in a plane normal to the path of the light beam, these frames being movable in their respective planes so as to be able to approach or to move away in pairs and thus to partially or totally interpose said gelatins on the light beam path. 8) Lighting device according to claim 7, characterized in that the gelatins of the same filter are of the same color. 9) Device according to claim 7, characterized in that the colored filters are of different colors. 10) Device according to any one of the preceding claims, characterized in that an uncolored filter, using a pair of gelatin (32 '", 33'") uncoloured similarly to the other pairs of gelatin on movable frames (26 "', 27"') said non-colored filter being able to blur the light beam more or less depending on its opening. 11) Device according to any one of the preceding claims, characterized in that the frames on which the gelatins are stretched are provided with means capable of sliding them on a slide forming a support (30,30 ', 30 ", 30"' ) defining the direction of their mobility. 12) Device according to any one of the preceding claims, characterized in that it comprises a shutter means, three colored filters, and a non-colored filter capable of making the light beam more or less blurred. 13) Device according to any one of the preceding claims, characterized in that the lenses movable axially in said plurality of lenses are part of an adjustable optical focusing sub-device (37) (commonly called "ZOOM"). 14) Device according to any one of the preceding claims, characterized in that said means capable of sliding the movable frames on which gelatin is attached and the plates constituting the shutter means are remotely controlled motors. 15) Device according to any one of the preceding claims, characterized in that it is implemented in a scenic lighting projector.

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