Architectural luminaries

Architectural luminaries utilize a common optical engine having a lamp coupled to an ellipsoidal reflector, a field stop aperture, and image-projecting lenses A color wheel, gobo wheel, and mechanical dimmer may also be included. A microlens element converts a spotlight optical engine into a wash light optical system. A multiple lens array provides variable diffusion. The optical engine is combined with an X-Y scanning mirror beam direction system in a substantially recessed housing for mounting in the ceiling of a building. The optical engine is combined with a pan-and-tilt yoke for greater range of coverage with an exposed luminaire.

FIELD OF THE INVENTION 
The present invention relates to lighting instruments and optical systems 
therefor, especially to a convertible optical system adaptable from a spot 
light projector to a wash light illuminator having variable diffusion 
property. 
DESCRIPTION OF RELATED ART 
Prior art lighting instruments are usually designed for a specific purpose, 
among those possible purposes being a spot light projector, a wash light 
or other general area illumination. A typical spot light, such as that 
shown in U.S. Pat. No. 2,076,240 to Levy, has an ellipsoidal reflector and 
a projection gate or field stop aperture with two or more lenses to 
produce a hard-edged beam capable of projecting a well-defined beam or 
projecting images of light pattern generators or gobos placed in the 
projection gate. A typical wash light, such as that shown in U.S. Pat. No. 
3,428,800 to Levin, has a lamp and reflector that are movable with respect 
to a Fresnel lens to produce a soft-edged, ill-defined beam that produces 
a smooth wash of light with a variable beam diameter. A wash light 
typically has no gate aperture. 
While an ellipsoidal reflector provides a region of minimal beam diameter 
near the secondary focus of the reflector, which can be advantageously 
used for beam shaping and the forming of images, and also for beam color 
control using small dichroic filters, projection lenses of a quality 
suitable for image projection provide only a limited range of beam 
divergence angles compared with Fresnel-type lenses, which are not 
suitable for image projection. 
Whereas all automated lighting fixtures produced to date are exposed 
fixtures, a great many architectural lighting fixtures, especially those 
for indoor use, are typically recessed into the ceiling of a building. 
Although exposed fixtures, particularly those of the moving head variety, 
can cover a wider range of lighting direction, not being limited by the 
reduced range of motion of moving mirror types, recessed fixtures tend 
less to detract from the general appearance or environmental design of a 
room since they are largely concealed within the ceiling. It is difficult 
to anticipate the wants or needs of architectural lighting customers, and 
the development of a product for production can be both lengthy and 
costly. It is therefore desirable to be able to produce either spot lights 
or wash lights in recessed or exposed fixtures, all of which resulting 
from a development program that uses as many parts in common as possible. 
SUMMARY OF THE INVENTION 
The preferred embodiment provides a convertible optical system for a light 
projector, the optical system being easily configurable from a spot light 
projector to a wash light projector to a wash light projector with 
variable diffusion. 
In accordance with one aspect of the present invention, a spot light 
projecting optical system comprising a light source optically coupled with 
an elliptical reflector, a field stop aperture, and an 
axially-translatable, image-projecting lens system is adapted to a wash 
light system by placing a wash lens in front of the lens system. 
In accordance with another aspect of the present invention, the wash light 
system described above is configured for variable diffusion by placing an 
axially-translatable, multiple lens array between the field stop aperture 
and the lens system, which includes the wash lens and the 
axially-translatable, image-projecting lens system. 
In an alternate embodiment, the combination of image-projecting lens system 
and wash lens is axially fixed and the multiple-lens array is made axially 
translatable. 
In accordance with another aspect of the present invention, the convertible 
optical system herein described can be configured as an exposed, 
moving-head luminaire or as a recessed luminaire with motorized mechanisms 
and automated functions.

DETAILED DESCRIPTION 
Lighting instruments disclosed herein are based upon a common optical 
engine. Referring to FIGS. 1-3, optical engine 10 includes a light source 
1, such as an electric lamp, optically coupled to an ellipsoidal reflector 
2 having a primary focus F1 and a secondary focus F2, the lamp and 
reflector forming a light beam 3 having an optical axis 4, the light beam 
converging at the secondary focus and diverging thereafter; a field stop 
aperture 5 formed in an aperture plate 6 located at the secondary focus; 
and image-projecting lenses 7 and 8 located along the optical axis 
downstream of the field stop aperture. The lamp, reflector, aperture plate 
and lenses are supported by a first frame assembly 11 that includes a main 
bracket 12, a lamp-support bracket 13, and a moveable lens carriage 14. 
The first frame assembly 11 maintains the lamp and reflector in 
substantially fixed relation to the aperture plate and allows the lenses 
to move axially along the optical axis with respect to the aperture plate, 
lamp and reflector for focusing the light beam at a desired throw length. 
The lens carriage 14 can be manually adjusted and fixed in axial position 
by means of a suitable screw clamp arrangement, but is preferably coupled 
to a linear actuator motor 15 mounted on the aperture plate to enable 
remote adjustment via an electronic control system. Additional motors 
16-18 can be mounted on the aperture plate for supporting an adjustable, 
mechanical dimmer 19, a rotatable color wheel 20, and a rotatable gobo 
wheel 21. An adjustable iris diaphragm (not shown) can also be mounted on 
the aperture plate and motorized to provide beam size adjustment. 
The color wheel 20, gobo wheel 21, and mechanical dimmer 19 are preferably 
motorized as shown, for example, in U.S. Pat. No. 4,779,176; U.S. Pat. No. 
4,800,474; and U.S. Pat. No. 5,590,954, which are hereby incorporated by 
reference. The motors are preferably operated by a suitable electronic 
control system of the type shown, for example in U.S. Pat. No. 4,392,187 
and in U.S. Pat. No. 4,980,806, which are hereby incorporated by 
reference. 
The optical engine 10 in the first embodiment, projects a beam of light 
which can be altered in color by the color wheel 20, can be altered in 
diameter by an adjustable iris diaphragm, can be altered pattern or shape 
by the gobo wheel 21, can be altered in intensity by the mechanical dimmer 
19, and can be altered in focus by the proJection lens system. The optical 
engine 10 is mounted in a suitable enclosure which also contains control 
electronics for operating the motors, a power supply for energizing the 
lamp, and a power supply for energizing the control electronics. The 
enclosure provides features for mounting the lighting instrument in a 
desired location. A lighting instrument containing the optical engine may 
take a variety of forms, two of which will be described here. 
As shown in FIG. 4, a recessed luminaire 28 includes the optical engine 10 
mounted horizontally in a generally rectangular enclosure comprising a 
second frame 30 and a housing 40. The enclosure is preferably sized to fit 
within framing members of a suspended ceiling or between ceiling joists. A 
motorized X-Y scanning mirror is provided to intercept the light beam and 
variably re-direct the beam as desired. The motors are operated by the 
control electronics in a known manner. Scanning mirrors of this type are 
well-known and are shown, for example, in U.S. Pat. Nos. 3,594,566; 
4,899,267; 5,089946; 5,333,102; in the international application WO 
96/36834; and in U.K Patent Application No. GB 2 106 233 A, which are 
hereby incorporated by reference. The lighting instrument can be operated 
in any orientation and may, for example, be mounted substantially 
vertically within a wall if so desired. 
As shown in FIG. 5, a typical enclosure includes second frame 30 supporting 
an L-bracket 32 at one end thereof. A pan motor 33 supported on the 
L-bracket further supports a tilt motor 34, which in turn supports a 
planar, beam-steering mirror 35. Light from the optical engine passes 
though an aperture 36 formed in the second frame 30, and strikes the 
mirror 35, is adjusted in elevation via actuation of tilt motor 34, and is 
adjusted in azimuth via actuation of pan motor 33. Brackets 37 and 38 
secure the enclosure within the ceiling of a building. Enclosure 40 
surrounds the luminaire on five sides to protect the optical and 
mechanical components from particulate contamination, and to isolate 
electrical components from nearby building materials. Brackets 37 and 38 
may be affixed to the second frame 30 as shown, or may alternatively be 
affixed to the housing 40 for mounting the housing into the ceiling as a 
first step, and then installing the rest of the luminaire assembled into 
the second frame 30 at a later time after the building construction and 
wiring installation has been accomplished. 
As shown in FIG. 6, a cover plate 39 having an exit aperture 41 is 
installed over the recessed luminaire to conceal the inner workings from 
view, except for the mirror 35 and motor 34 which must necessarily be 
exposed to some extent for allowing the light beam to exit the enclosure. 
Since from time to time it will be necessary to replace the lamp and may 
be desirable to exchange the color wheel 20 or gobo wheel 21 for wheels 
having different color filters or different projectable images, the cover 
39 can be removed and the optical engine 10 can be pivoted partially out 
of the enclosure into a maintenance position shown in FIG. 7. The first 
frame assembly 11 may be attached through a hinge device 49 to the second 
frame 30 to allow for the pivoting action. This maintenance position 
allows access to the lamp and to other optical, electrical or mechanical 
components of the optical engine 10. 
As shown in FIGS. 8 and 8A, the optical engine 10 can be mounted for 
pivotal motion in a motorized pan-and-tilt yoke 50. In practice, the 
optical engine would be enclosed by suitable and decorative covers, but 
the engine itself would be directly mounted to the yoke arm. 
Alternatively, a lamp housing structure could be mounted to the yoke and 
the optical engine could be installed in the lamp housing structure. Pan 
and tilt enclosures of this type are well-known and have been shown, for 
example, in U.S. Pat. Nos. 1,827,797; 3,209,136; 4,392,187; 4,701,833; 
5,367,444; and 5,590,955, which are hereby incorporated by reference. The 
pan and tilt motors are operated by the control electronics in a known 
manner. Control and power supply electronics are mounted within the yoke 
arms and mounting enclosure as shown, for example, in U.S. Pat. Nos. 
4,701,833 and 5,367,444, which are hereby incorporated by reference. 
Thus, as described above, the basic optical engine 10 in a first, spot 
light, embodiment is used as a primary building block for creating a 
typical pan-and-tilt spot lighting instrument and is also used for 
creating a recessed spot lighting instrument utilizing an X-Y scanning 
mirror. 
Referring to FIG. 9, an optical engine 10' in a second embodiment further 
includes a micro-lens array 22 supported downstream of the projection lens 
system on the movable lens carriage 14. In this second, wash light, 
embodiment, the gobo wheel is preferably removed since projection of 
images is typically not an object of a wash light. The gobo wheel can be 
replaced by a second color wheel 26 for providing a wider range of colors 
such as described in U.S. Pat. No. 4,800,474, which is hereby incorporated 
by reference. 
The micro-lens array 22, as shown in FIG. 10, is preferably a clear disk 23 
having a plurality of tiny convex lenslets 24 arranged in concentric 
circles on one face of the disk. Depending upon the size of the lenslets, 
the micro-lens array can provide any one of a variety of beam-angle 
dispersions; for example, 7.5 degree, 15 degree, or 30 degree beam angles. 
A mask 25 at the center of the disk blocks light rays radiating directly 
from the light source to prevent creation of a "hot spot" in the center of 
the beam. When mounted on the moveable lens carriage, downstream of the 
imaging lens system, the micro-lens array both enlarges the projected pool 
of light and softens the edges thereof. The actual beam angle can be 
varied somewhat, thereby varying the size of the pool of light, by 
adjusting the moveable lens carriage axially along the beam path. 
The basic optical engine 10' in a second, wash light, embodiment is used as 
a primary building block for creating a typical pan-and-tilt wash lighting 
instrument and is also used for creating a recessed wash lighting 
instrument utilizing an X-Y scanning mirror as described above. 
Referring to FIG. 11, an optical engine 10" in a third, variable-diffusion 
wash light, embodiment includes a multiple-lens array 60 preferably 
positioned upstream of the imaging lens system. The multiple-lens array 
60, as shown in FIG. 12, preferably comprises a transparent plate 61 
having, on at least one surface thereof, a plurality of convex lenslets 62 
of cylindrical or other shapes in geometric or other arrangement for 
increasing divergence of light rays passing therethrough. The 
multiple-lens array 60 can be mounted in a fixed axial position, and 
cooperates with the axially-translatable lens system mounted on the 
moveable lens carriage 14 so that beam divergence is varied due to the 
effect of moving the imaging lens system axially with respect to the 
multiple-lens array 60, lamp 1 and reflector 2. Alternatively, the 
combination of imaging lenses 7 and 8, and microlens 22 can be mounted in 
a fixed axial position while the multiple-lens array is mounted for axial 
movement with respect to the lamp and reflector. 
Control electronics for the luminaire, as shown in FIG. 13, comprise a 
printed circuit board assembly 70 having a central processing unit (CPU) 
71, preferably in the form of a microprocessor, and associated memory 72 
therefor interconnected by a bus system 73 carrying address, data, and 
control signals. A communications circuit 74 coupled to the microprocessor 
via the bus system communicates with an external supervisory controller 90 
for directing the operation of plural such luminaries. A motor-driver 
interface circuit 75 coupled to the microprocessor via the bus system 73 
operates motors for adjusting the positions of the color wheel, the gobo 
wheel, and the pan and tilt or X-Y scanning motors. If additional 
motorized mechanisms are provided for adjusting the dimmer, adjustable 
iris, image-projecting lens system, and/or variable-diffusion multiple 
lens array, a second control board 80 is provided having a microprocessor 
81, memory 82, and motor drivers 85. The two control boards are linked 
from serial bus communication link circuit 76 through the serial data link 
77, which is internal to the luminaire, to the serial bus communication 
link circuit 86. The second, slave, controller is directed in operation by 
the first, master, controller. Commands received from the external, 
supervisory controller are relayed from the master control board via the 
internal serial data link 77 to the slave control board, which then 
executes the commands. 
The motor systems may include DC servomotor systems, stepper motor systems, 
or a combination of both. Stopper motor systems can be driven "open-loop" 
or may be provided with position-detecting sensors 88 coupled to the 
control system via sensor interface 87. Techniques for operating motor 
systems of these types are shown, for example, in U.S. Pat. No. 4,980,806, 
which is hereby incorporated by reference.