Lighting device

A lighting device comprising one or more light sources placed in respect to a concentrating concave or echelon main reflector, with the light emitted by the light source(s) being reflected by the main reflector so as to create a projected pattern of light to be directed onto a subject to be illuminated, a focusable light being achieved by shifting means capable of displacing or tilting the light source(s) with regard to the optical axis of the reflector. Said shifting means are apt to displace said at least one light source in a direction or at an angle to and from said optical axis of said reflector, in a plane substantially perpendicular to said axis, or to tilt the at least one light source(s). The light source(s) is(are) placed around said optical axis of the reflector and are movable or inclinable in a direction away from the optical axis of said reflector.

BACKGROUND OF THE INVENTION 
The invention is relative to the field of lighting in which lighting 
devices or luminaires are used comprising one or several light sources 
placed in regard to a reflector to illuminate directly a subject, e.g. in 
luminaires used in television studios. 
Such reflector light sources are well known which furthermore concentrate 
or focus the light, thus changing the angle lit. This an be achieved in 
several different ways. 
The most common lighting device of this kind is provided with shifting 
means for moving backwards or forwards longitudinally along its optical 
axis the light source placed within the reflector so as to vary the 
projected pattern of light. However, such lighting devices present the 
following disadvantages: 
When the light source is advanced to a maximum degree, the end of the lamp 
may protrude forward thus exposing it to potential breakage. Also a 
percentage of light emitted by the light source is consequently lost since 
it is no longer captured and reflected by the reflector. Furthermore, the 
light source may come in contact with accessories attached to the front of 
the reflector. 
The housings and focusing systems of the lighting device must be made large 
in size in order to permit the above mentioned movement. 
When the light source is moved backwards, it goes beyond the rear limit of 
the reflector, causing an increasing amount of light to be wasted since 
the reflector no longer receives this light and, therefore, cannot reflect 
it forward as desired. 
When a small-size light source is used and when a wide-angle light pattern 
is desired, there is a "hole in the middle" since no light is reflected 
there. 
Light devices have also been made with two light sources mounted 
eccentrically within a reflector and rotated around the optical axis of 
the reflector. The use of this type of fixture is very limited, due to the 
light pattern variation always being projected co-axially in the same 
fashion, in an uneven manner around the optical axis. 
A variation of this type of lighting device has been made in which the 
rotational movement of two light sources is coupled to a longitudinal 
movement of them backwards and forwards along the optical axis of the 
reflector, so that the light can be more or less focused. However, its 
utility is extremely limited. 
Lighting devices having multi-filament lamps have also been used. The 
filaments are in this case placed physically at different fixed places 
within the lamp so that the surrounding reflector receives the light 
coming from different angles, thus projecting the light forward in a 
different manner. This system has certain disadvantages and limitations 
and except for automobile head lights, this system is rarely used since: 
Special multi-filament lamps must be used. 
The light pattern is limited and fixed by the above number of filaments 
within the lamp and their placement. 
It is not continuously variable. 
Another type of lighting device uses a reflector that has two separate 
sections with the same optical axis. A lamp is used in each level of the 
reflector and each section has different optical characteristics and 
diameter. So by switching on one lamp or the other, or both, the lighting 
effect changes. However, this device is rather complicated to produce and 
rather limited in use. 
Clusters of light sources placed around the optical axis of a reflector are 
also known, but such systems if focusable, do so by changing reflectors or 
by moving the lamps backwards and forwards longitudinally along the 
optical axis. 
Also fixed focus lighting fixtures are known in which the lamp is inserted 
and held at an angle to the optical axis, so as to have its base outside 
the reflector at the side rather than to the rear with the light emitting 
surface of the lamps placed along the optical axis of the reflector in a 
fixed position. So there are no means to vary the light. 
Fixed ceiling lights in the 60 cm.times.60 cm size range exist, but the 
angle they light and the direction of the light cannot be changed. 
Attempts are made to get around this deficiency by placing in front of 
certain models, expensive known elements such as light absorbing gridspots 
to reduce the angle lit, and light reflecting grid elements to reflect 
light to the side at a fixed angle. These accessories are inefficient, 
expensive, and non-adjustable. 
The banking together of a number of lights is well-known and much used, but 
all existing such fixtures are made up of simply a series of individual, 
non-adjustable lights, mounted side to side. So the angle lit by these 
arrays of lights is not adjustable, and the lack of the use of additional 
mirror reflecting surfaces common for all the lights, means that there is 
no increase in light output and there is no mixing of the light by these 
mirror surfaces. 
SUMMARY OF THE INVENTION 
This invention is relative to a lighting device which overcomes the 
disadvantages of the prior art lighting devices. 
Specifically, this invention is directed at making a lighting device using 
one main reflector and which is capable of varying the projected pattern 
of light either symmetrically or asymmetrically, and to do this without 
moving the light source(s) backward or forward longitudinally in the 
direction of the optical axis of the reflector or by rotating them around 
the optical axis of the reflector. As there is no backward and forward 
movement of the light source, the depth of the luminaire can be minimized. 
Furthermore, the light source(s) is(are) allowed to be moved without 
interference from the accessories placed on its front face. 
The lighting device made according to the invention makes it possible to 
have a focussable light having a variable angle from less than 30.degree. 
to over 100.degree. with a very high light output and efficiency. When 
used with fluorescent lamps, the lighting device of the invention achieves 
up to or even more than 100 Candelas per watt vs. 10 to 30 Candelas per 
watt being attained by other presently being made fluorescent lamp 
devices, which in addition are not focusable. 
The lighting devices made according to this invention can be used with one 
or more light sources which are placed in a position to illuminate a 
concentrating concave or echelon reflector. Individual reflectors for each 
light are not needed. It is also possible to have interchangeable 
lightheads and interchangeable reflectors. 
Furthermore, with the invention, normal lamps can be used instead of 
special "bi-focal" or "multi-focal" lamps. 
The lighting device according to the invention comprises at least one light 
source placed in a position to light a main reflector. The light emitted 
by the light source is reflected by the reflector so as to create a 
projected pattern of light to be directed onto a subject to be illuminated 
with, a focusable light being achieved by shifting means capable of 
displacing or tilting said at least one light source with regard to an 
optical axis of the reflector. 
According to an important aspect of the present invention, the shifting 
means are apt to displace said at least one light source in a direction to 
and from said optical axis of said reflector, in a plane substantially 
perpendicular to said axis. 
According to a specific embodiment of the invention, at least two light 
sources are placed around said optical axis of the reflector and being 
movable in a radial direction with regard to the optical axis of said 
reflector. 
Preferably, the light sources are regularly placed around said optical axis 
of the reflector. 
According to an other embodiment of the invention, a fixed light source is 
placed in the optical axis of said reflector, and used in conjunction with 
other movable or tiltable light sources. 
According to a further embodiment of the invention, the device comprises at 
least two light sources and said shifting or tilting means which are 
capable of moving or tilting simultaneously said light sources. 
According to a further embodiment of the invention, the lighting device 
comprises at least two light sources and said shifting means are capable 
of moving or tilting separately the light sources. 
According to a further aspect of the invention, the shifting means comprise 
a guide plate having at least one guide slot through which passes an 
extension of the base of said at least one light source, a cam plate being 
placed under the guide plate and having at least one cam cooperating with 
a light source base, the guide plate and the cam plate being capable of a 
relative rotating movement so as to displace the base of said light source 
base in said direction to an from the axis of said reflector. 
According to a further aspect of the invention, the guide slots of said 
guide plate are rectilinear slots extending radially from the optical axis 
of said reflector and the cams of the cam plate are curved. 
According to a further aspect of the invention, the cams of the cam plate 
are slots. 
According to a further aspect of the invention, the light source base is 
separated into different sections each for groups of one or more light 
sources, and the shifting means are used to control the tilting of each 
section which is inclinable to and from the optical axis of the reflector. 
Different means for controlling the tilting angle exist enabling the user 
to change the light pattern by varying the angle for instance by: turning 
a knob; operating a lever, or by an electric motor. 
According to a further aspect of the invention, the device comprises at 
least two light sources of different nature such as incandescent halogen 
lamps, high frequency, fluorescent tubes, discharge lamps, electronic 
flash tubes. 
According to a further aspect of the invention, the housing in which the 
shifting means are placed can be separated from said reflector in order to 
be replaced by an other housing with a different set of light sources or 
to use different interchangeable reflectors with the same lighthead. 
Other features, advantages and objects of this invention will become 
apparent from the following description of embodiments of the invention 
taken in conjunction with the figures.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
FIGS. 1-3 show a first embodiment of the invention. The lighting device 
shown comprises two light sources 10 in form of U-shaped light tubes which 
are placed inside a reflector 11, on opposite sides of the central optical 
axis 12 of this reflector. 
The bases 13 of the lights sources 10 are disposed in a central opening 14 
of the reflector on a base plate 15 constituting the front side of a 
housing 16 of the lighting device. The base plate 15 and the housing 16 
have preferably a cylindrical form and the cylindrical side wall of the 
housing is extending above to base plate 15 so as to form a circular space 
17 in which the bases of the light sources are disposed so that their 
light emitting parts start from a point near the level with the reflector 
opening. 
The housing 16 preferably contains the electronic circuitry, ballasts and 
power supplies 18 of the lighting device. A main electrical input has the 
reference number 19 in FIG. 1. 
The lighting device further comprises shifting means capable of displacing 
the light sources 10 with regard to the optical axis 12 of reflector 11. 
For that purpose, the base plate 15 contains according to an embodiment of 
the invention rectilinear guide slot 20 (FIG. 2) constituting a guide 
plate for the lamp or tube bases 13 which are provided with an extension 
21 passing through the slots. The dimension of this extension 21 is 
adapted to the width of the slot to insure an easy displacement of the 
extension along the slot. 
The slots 20 are radially displaced and preferably but not necessarily 
aligned so as to face each other on opposite sides of the optical axis 12 
of the reflector 11 and they move outward in a perpendicular manner to 
this axis 12. Consequently, the tube bases 13 can be displaced in these 
guide slots 20 in a direction to and from the optical axis of the 
reflector, in a plane substantially perpendicular to this axis. 
The shifting means further comprises a cam plate or disc 22 disposed 
immediately under the guide plate 15 in the housing 16 where it is mounted 
so as to be able to rotate around an axis which coincides with the 
longitudinal axis of the housing. The cams are in this embodiment in form 
of two curved slots 23, but they could of course as an alternative be in 
form of grooves made on the side of the cam disc facing the guide plate 
15. The cams could also be constituted by additional guides attached to 
the cam disc 22. 
Each curved slot 23 has one of its ends near the center of the cam disc 22, 
whereas the opposite end is near to the periphery of the disc depending on 
the desired amount of movement. 
The extensions 21 of the tube bases 13 extend into the cam slots 23 so as 
to be moved along the cam disc when this latter is rotating. The width of 
the cam slots 23 are adapted to the dimension of the extensions 21 so as 
to facilitate their sliding in the slots. 
For controlling its rotation, the cam disc 22 is coupled to an arm 24 
protruding from the housing through an oblong opening 25 in the wall. The 
shifting means according to this embodiments works as follow. 
FIG. 2 shows in solid lines the position where the light sources bases 13 
are in their end position near to the periphery of the guide plate 15 and 
in broken lines the position where they are in their end position near to 
the center of the plate 15. They are moved from the first position to the 
second by rotating the cam disc in FIG. 3 and can of course take any 
intermediary position. 
By moving the light sources to and from the optical axis of the reflector, 
the angle of incidence of the light rays hitting the reflector changes, 
thus changing their angle of reflectance. Hence, it is possible to direct 
the light rays to different places in space by varying the placement of 
the light sources on the guide base plate 15. Also as a light source 
approaches the reflector surface, it subtends a bigger angle causing its 
angle of reflectance to increase. These facts are used in the invention to 
create a new, versatile and efficient luminaire. 
For use in television studios where the lights are hung from above, the 
control means for displacing the light sources within the reflector is 
advantageously operated by a pole which is manipulated from the floor. 
FIG. 1 also shows in broken lines alternative control means of the cam disc 
22. They comprise a central shaft 26 connected with the disc 22 and having 
one end attached to a turning knob 27 placed outside the housing 16. 
For use in television studios, the turning knob 27 can in the above 
mentioned case be operated by means of a cardan or universal joint to 
which is attached a turning cup. 
It would of course be possible to have another type of shifting means as 
e.g. a cone, the top of which enters between slidingly mounted and spring 
biased light source bases so as to displace the bases toward a peripheral 
position when penetrating further between the bases. 
Other shifting means, including individual manual means, could also be 
provided so as to move the light sources independently of each other. 
FIGS. 4-6 show some alternative embodiments having the same type of 
shifting means as the embodiment already described, but with a various 
number of light sources. 
In FIG. 4, bases 13 of one single light source can take a position either 
in the optical axis of the reflector or be moved along a radially 
extending guide slot 20 toward the periphery of the guide plate 15. In 
FIGS. 5-6, there are 3 respectively 4 light sources guided in regularly 
disposed radially extending guide slots 20 on the guide plate 15. 
The movement of the light sources disposed as indicated in FIGS. 5 and 6 
should be limited to where a "hole in the middle" appears so as to insure 
a homogeneous lighting pattern. 
To eliminate this "hole in the middle", FIG. 7 illustrates an advantageous 
embodiment with a light source having its base 13' centrally placed in a 
fixed manner in the central optical axis of the reflector 11. In the shown 
arrangement, two radially movable light source bases 13 are disposed on 
opposite sides of the fixed light source. Such an arrangement increases 
the total amount of light and also permits laterally placed light sources 
to be moved further away with regard to the optical axis of the reflector 
11 in order to obtain a wider lighting angle, without creating a "hole in 
the middle" which has less light. 
Of course, such a centrally fixed light source could be used with any 
number of movable light sources. In tests carried out by the applicant, up 
to 8 light sources have been used with success. 
A lighting device made in this manner, using a single row of light sources 
such as shown in FIGS. 2 and 7 will thus permit the light pattern to be 
made in a linear manner. This is especially advantageous whenever one 
wishes to light up backgrounds in studios or for lighting several people 
sitting in a row, such as at a News Desk. This also permits them to be lit 
without changing the lighting effect used on the set behind them, since if 
they are being lit in a horizontal manner, there will be little light 
falling on the scenery behind them, and no light is wasted by falling on 
the floor below their desk. 
Furthermore, the housing 16 is advantageously mounted to the reflector 11 
by quick release means such as a latching device to make it possible to 
have interchangeable housings provided with shifting means according to 
the invention. 
FIG. 8 shows another embodiment of the invention without any base plate on 
which the light source bases can move. In this case, the extensions of the 
light source bases are placed in slots 28 made directly in the wall of the 
reflector 11. The slots 28 extend outwards in the reflector in a plane 
which is substantially perpendicular to its optical axis 12. 
The light source bases are attached to simple shifting means like e.g. 
push-and-pull and locking devices which are well known to one skilled in 
the Art. 
The lighting device according to the invention makes it possible to use 
combinations of different kinds of light sources such as incandescent 
halogen lamps, fluorescent tubes powered by either low frequency or high 
frequency ballasts, discharge lamps of different kinds, electronic flash 
tubes. 
Since additional means of controlling the light are often desirable, 
mounting means are provided for using different accessories. 
These means for mounting can comprise a ridge 29 incorporated into the 
reflector 11 to hold gridspots, diffusers, colour filters, prismatic 
refracting light intensifiers. An outer lip 30 of the reflector 11 can be 
provided to hold different accessories such as pivoting barn doors 31, 
clip-on colour filters, clip-on light reflecting intensifiers. The 
mounting means may also comprise a ring for linking reflectors together in 
either a 45.degree. or 60.degree. manner or for attaching either an extra 
large size reflector or lightbox. 
Means can also be provided either on reflector 11 or on the rear housing 16 
to attach an L-shaped or U-shaped yoke for holding and tilting the 
lighting device in a conventional manner or for the holding of the 
lighting device on a flexible goose-neck or pan-tilt mount. 
FIGS. 9 through 14 show another embodiment of the invention in which the 
lighting angle is varied by inclining the light source(s) instead of 
varying the distance of their bases from the optical axis of the 
reflector. If desired this system can be combined with the previously 
described one. 
This system has numerous advantages. It is cheaper to manufacture since it 
is simpler and uses fewer parts, and it avoids having a "hole in the 
center" lighting effect. The lamp bases 13 remain in fixed positions in 
their respective difference sections of lamp base 15. These separate 
sections are then inclined with respect to the optical axis 12 of the 
reflector. 
FIG. 9 is a schematic top view as shown in FIG. 15 of a base plate 15 
divided along line 29 into two sections, shown with one lamp base 13 on 
each section. However, two or more lamps can be placed per section. Each 
section has means 30 for holding it within the housing enclosing it. The 
angle of the sections with respect to the optical axis of the reflector is 
controlled either by keeping the center axis or point in place and by 
moving backwards and forwards the outer edges of the base plate 15, or by 
keeping the outer edges in place and by moving backwards and forwards the 
center axis or point of the base plate. 
The individual sections are linked together by a hinging means such as a 
hinge 33, or base plate 15 can be made of a single plastic plate with a 
flexible section along line 29 so as to serve as a hinge. The different 
sections can also be separate parts held together by a center piece 31 
onto which a shaft 35 can be attached which permits their respective angle 
to be changed when shaft 35 is moved backwards and forwards. 
FIG. 10 is a side schematic view showing the two sections of base plate 15 
in a flat position with lamps 10 parallel. 
FIG. 11 is a side schematic view showing the base plate 15 with its 
sections in a diverging wide angle position. In this configuration lamps 
10 are pivoted further away from the optical axis of the reflector, and 
are closer to the reflector 11 (FIG. 13), thus subtending a bigger angle. 
So the angle lit by the reflector is increased. 
FIG. 12 is a side schematic view showing the base plate 15 with its 
sections in a converging concentrated position. Thus lamps 10 are closer 
together forming a smaller size light source which is closer to the 
optical axis of the reflector and deeper within the reflector, causing an 
increase of light of light over a smaller angle. 
FIG. 13 is a schematic cross section view depicting the tilting movement of 
the lamps 10. Generally a .+-.15.degree. movement 50 of the lamps 
suffices, but this can vary depending on the placement of the lamps on 
base plate 15, the length of the lamps, the angle variation sought, the 
design of the reflector, etc. The movement necessary for the desired angle 
variation is advantageously obtained by moving the center of base plate 15 
in the direction of arrow 34 and controlled for example by axis 35 and by 
turning knob 36 or by an electric motor (not shown) or by a lever similar 
to lever 24 of FIG. 1 attached to axis 35, or by moving center axis 29 in 
and out by using points 32 as in FIG. 15 or FIG. 9. 
FIG. 14 is a schematic top view of a base plate with four lamp sockets 13 
designed for holding four lamps 10, with individual sections 37 for each 
lamp. This type of base plate gives a variation in the angle lit that is 
symmetrical. Other base plates can be designed for use with other 
quantities of lamps. The individual sections are held in place like the 
examples previously given and their angle similarly controlled. 
FIG. 15 is a schematic top view of a base plate divided into two sections 
in which two lamp sockets 13 are placed on each section whose angle can be 
varied. This version differs from FIG. 14 in that when the lamps are 
tilted, more variation in the angle lit occurs in one plane compared to 
the other. 
FIG. 16 illustrates with a side elevation view one version of the holding 
end of the control shaft attached to the center of base plate 15. This 
piece holds all of the sections in place at their center points, while 
permitting them to be tilted backwards and forward by control shaft 35. 
FIGS. 17 and 18 show another version of how lamp sockets 13 can be mounted 
on base plate 15. Two or more lamp sockets 13 are mounted on plates 51 
which in turn can be mounted and rotated around point 52. FIG. 17 shows 
the lamp aligned horizontally while FIG. 18 shows the lamps in vertical 
position moved closed to each other by their lateral movement. These 
rotating plates 51 can also be used with the previously described base 
plates designed to be inclined along axis 29. 
FIGS. 19 and 20 show another embodiment of this invention of particular 
interest for making overhead ceiling lights which are adjustable both in 
the direction they light and in the angle lit, and which have a much 
higher efficiency than existing lights in the 60 cm.times.60 cm size range 
which only light downwards in a non-controllable direction and which have 
no control over the angle lit. 
My invention makes it possible to make such lights which can direct the 
light either downwards or sideways at an attack angle that can be fixed or 
variable. And its design also permits the lighting angle to be varied or 
set as desired. 
By using specially designed echelon reflecting elements, it is possible to 
make such lighting fixtures that can be retro-fitted in the ceilings in 
spaces presently occupied by known lighting fixtures with fixed lighting 
characteristics. 
It is advantageous to use a lighting fixture made according to my 
invention, since while being lodged in a fixed position in or on the 
ceiling, it can light a painting or decoration on the wall next to it. And 
its angle can be varied in order to light up different size areas. Also if 
two separate light sources are used, two different such lighting zones can 
be had and adjusted using just one lighting fixture. Furthermore, the 
efficiency of these fixtures are far higher than present light fixtures 
using diffusers in front of the lights. 
FIG. 19 is a schematic top view of the fixture. 36 is the main 
concentrating reflector which can either be concave in form or an echelon 
reflectors as illustrated here. Should one wish to reduce tooling costs, 
this echelon reflector can be made up of several smaller sections 41 
united together as desired. 
Light source 42 (FIG. 20) can be of different types such as an incandescent 
lamp, fluorescent lamp, discharge lamp, electronic flash, et al. Means are 
provided to permit its placement at different distances from reflector 36 
and at different points as regards the optical axis of the reflector. Thus 
by selecting a point closer to or further away from reflector 36, one can 
select the angle lit, and by moving it over different zones of 36, the 
light can be directed in space as desired. A vertical shaft 37 is shown in 
a corner of the fixture illustrating one way that can be used to adjust 
the distance of light source 42 which is shown mounted on lateral bar 38. 
However, one or more vertical shafts 37 can be placed elsewhere and one or 
more lateral or radial bars 38 can be used. Lateral or radial bars 38 can 
be rotated as indicated by arrows R. 
FIG. 20 is a schematic cross section view of this version of a device made 
according to the invention. Arrows 44 show the zone over the echelon 
reflector 36 where light source 42 can be moved, coupled in this case with 
reflector 43 to gather light which would not fall on reflector 36. Arrows 
45 show how the height of the light source 42 can be selected so as to 
obtain the desired lighting angle. This angle is increased as the distance 
45 is reduced, and the angle is reduced, with a corresponding increase in 
light output, as the distance is increased up to that of the focal length 
of the reflector 36. 
Light can be reflected sideways away from the optical axis 12 by displacing 
light source 42 in the opposite direction towards the opposite edge of 
reflector 36. In order to illuminate reflector 36 more evenly, means are 
provided to permit light source 42 to be tilted towards the center of 
reflector 36. 
Another embodiment of my invention is of interest principally for lighting 
cyclorama backgrounds or for front lighting in which two or more fixtures 
made according to this invention are mounted together with their light 
being reflected by one or more mirror reflectors common to them all. 
FIG. 21 is a schematic perspective view of this embodiment of the present 
invention in which four fixtures 46 made according to this invention are 
placed side by side and surrounded by one or more mirror reflecting 
surfaces 47. Other configurations can be used such as square, hexagonal, 
etc. each light can have its light filtered by color filters 48 placed 
across its front face. 
The mirror surfaces 47 have two roles: they increase light output by 
capturing and reflecting forward light which would be wasted going to the 
side. They mix the light coming from all the fixtures 46 since each 
reflecting surface 47 is a common reflector used jointly by all them all. 
The mixing together of the light by reflecting surfaces 47 is especially 
advantageous when lighting backgrounds with red, green and blue light. A 
common focusing control (not shown) permits the lighting angle of the 
whole bank of lights to be varied. Also each light can be dimmed 
separately or together by known means of dimming.