The subject disclosure relates to electrical lighting systems and more particularly to a lighting system employing LED light fixtures to illuminate an auditorium or similarvenue.

Incandescent lighting systems for illuminating theatres, auditoriums and the like have been used in the past.

WO2012/129243 discloses a light fixture having a plurality of LED light bars, each of which is individually dimmable.

There is provided an auditorium lighting system comprising: a plurality of LED light fixtures located in a ceiling of the auditorium; a power control system; wherein each LED light fixture comprises a fixture body, each fixture body of each LED light fixture mounting a plurality of LED modules; characterised in that the plurality of LED modules comprise two different types of LED modules, comprising: first and second high intensity light LED modules for providing high intensity full level lighting, located at opposite ends of the fixture body; and one or more ambience LED modules for providing exclusively low level ambient lighting; and in that said power control system is configured to collectively switch said one or more ambience light LED modules of each LED light fixture 'on_ and 'off_ and separately to collectively switch said first and second high intensity LED modules 'on_ and 'off_ to thereby provide either low level ambient light or high intensity full level lighting to said auditorium.

There is also provided an electric lighting fixture comprising a fixture body mounting a plurality of LED modules, characterised in that the plurality of LED modules comprise two different types of LED modules, comprising: at least first and second high intensity light LED modules for providing high intensity full level lighting, one positioned at each opposite end of said fixture body; and at least one ambience light LED module for providing exclusively low level ambient lighting, positioned between said first and second high intensity light LED modules.

A selection of optional features are set out in the dependent claims.

• Fig. 1 is a side schematic view illustrating an auditorium lighting system according to an illustrative embodiment;
• Fig. 2 is a perspective view of the lighting system of Fig. 1;
• Fig. 3 is a perspective view of a lighting fixture employable in the system of Fig. 2;
• Fig. 4 is a first cross-sectional view of the fixture taken at IV-IV of Fig. 3;
• Fig. 5 is a second cross-sectional view of the fixture taken atV-V of Fig. 3;
• Fig. 6 is a detail view illustrating cooperation of the fixture of Fig. 3 with adjacent sealingtile; and
• Fig. 7 is a perspective end view showing an illustrative installation of the fixture of Fig. 3.

An auditorium lighting system 11 according to an illustrative embodiment is shown in Figs. 1 and 2. It should be understood that as used here, the term 'auditorium_ encompasses theaters such as conventional 'movie_ theaters.

The lighting system 11 employs a plurality of light fixtures 13 installed in or attached to a ceiling 15 above a floor 21. These light fixtures 13 can be installed at regular or irregular spacing intervals so as to achieve uniform illumination of the floor 21, which typically slopes downwardly in a multi-level, "stadium style" arrangement and on which a number of seats are positioned, typically separated by one or more aisles. In other applications, the floor 21 may be flat.

A junction box 16 containing a plurality of LED drivers, for example, three drivers, is shown attached to the front interior wall 17 of a projection booth 18. The junction box 16 may be positioned elsewhere in the projection booth 18 in various embodiments or in another easy-to-access location, such as, for example, above a T-bar grid at the cross aisles. The junction box 16 may include controls, dimmers, surge protection, emergency back-up equipment and supplies electrical power to the light fixtures 13, as well as dimming capability.

Fig. 2 schematically illustrates the power feeds 23 to the fixtures 13 from the junction box 16 as three dashed lines. Remote positioning of the power system as illustrated in Figs. 1 and 2 makes wiring, dimming, and maintenance easier to manage.

An illustrative light fixture 13 is shown in Fig. 3. The fixture 13 includes an elongated extrusion 29, which provides a mounting surface or surfaces 30 for a plurality of LED modules 31, 33, 35, 37, 39, 41. The extrusion 29 further has respective junction boxes 43, 45 and horizontal flanges 47, 49; 51, 53 at each end. The junction or "splice" boxes 43, 45 provide faster and easier wiring, while the flanges 47, 49; 51, 53 assist in mounting the fixtures 13 to cooperate with adjacent ceiling tile. Fig. 6 illustrates the manner in which the flanges 47, 49; 51, 53 accommodate ceiling tile 81 in one illustrative embodiment.

The pairs of LED modules 31, 33; 39, 41 at opposite ends of the extrusion 13 are high intensity modules, which provide light for periods of cleaning or other maintenance. As illustrated in Figs. 4 and 5, the lighting system 11 employs high intensity modules, e.g., 31, 33 which are angled to the horizontal at an acute angle θ of, for example, 20° (degrees) and are aimed in opposing directions in order to increase the spread of light, thereby necessitating fewer fixtures in some embodiments. In addition, lenses or optics, e.g., 91, are employed in each high intensity module 31, 33 to produce a relatively intense light beam having, for example, a full width half maximum angle of 12 degrees.

Additionally, the center LED modules 35, 37 are ambient lighting modules configured to provide ambient light to illuminate the theater or auditorium, for example, during intermission periods. Other componentry shown in Figs. 4 and 5 includes the fixture housing extrusion 61, a bottom cover 78, a printed circuit board assembly ("PCBA") carrier 79, a PCBA carrier retention screw 75, a plastic dome lens 77, splice box 69 and splice box retention tab 67, electrical connector body 65, and ceiling tile flange 63. In one embodiment, the extrusion 61 may be an aluminum extrusion and the bottom cover 78 may be die cast aluminum. In one embodiment, the extrusion 61 and bottom cover 78 may be constructed as illustrated in U.S. Patent Publication 2013/0279180 A1 published October 24, 2013, the contents of which are incorporated in their entirety herein.

Each LED module 31, 33, 35, 37, 39, 41, may comprise a circuit board with one or more LED emitters mounted thereon. In one embodiment, the high intensity modules 31,33; 39, 41 employ 3 emitters e.g. 40, while the ambience modules 35, 37 employ 11 emitters. In one embodiment, each emitter of the ambience modules may have an output of 40 lumens at a full width half maximum angle of 120°.

The LED modules 31, 33, 35, 37, 39, 41 are configured in pairs and each may be six inches in length positioned in an extrusion 29 which is 42 inches in length, together with two splice boxes 69, resulting in a total fixture length of 47¾". Another embodiment may employ an eighteen inch long extrusion having three LED modules, together with two splice boxes 69, resulting in a total fixture length of 23¾". For example, such an embodiment may employ one central ambience LED module, flanked on either side by a high intensity LED module where the high intensity LED modules are angled at 20 degrees to the horizontal and oppositely directed.. In one embodiment, the relatively dim ambient intermission lighting may provide 2-4 foot candles of total light, while the full level, high intensity "cleaning" light modules may provide 6-9 foot candles of total light. In various embodiments, the light delivered by the modules may be adjusted based upon the ceiling height at the location where a particular fixture 13 is positioned.

The ambience modules 35, 37 may be collectively switched "on" or "off" at the same time, and the high intensity modules 31, 33; 39, 41 may also be collectively switched "on" or "off" at the same time. When the high intensity modules are collectively switched "on", each module 31, 33, 39, 41 is powered "on" and provides high intensity illumination. Similarly, when the ambience modules 35, 37 are collectively switched "on", each ambience modules 35, 37 is powered "on" and provides ambient illumination. In one embodiment, the ambience module 35, 37 are collectively switched or turned "on", while the high intensity modules 31, 33; 39, 41 are held or switched "off" and vice versa. In a dark state of the auditorium, all of the modules 31, 33, 35, 37, 39, 41 are in the "off" state.

Fig. 7 illustrates an attachment eyelet 51 on splice box 43 for attaching a fixture 13 by fasteners, e.g. 52, to a cooperating ceiling grid structure 84. Fixtures 13 may also be suspended by wires which terminate at structural elements of the building above the ceiling grid or by other mechanisms. Fig. 7 further illustrates electrical power cable 85 and cable sheath 87 held in place by a clamp 87. In one embodiment, two-circuit wiring is provided to enable individual on-off and dimming control of the high intensity modules 31, 33; 39, 41 and the ambient lighting modules 35, 37. In one embodiment, the junction boxes 43, 45 permit lead wires from the power supply to be connected by simply "poking" them in, and one fixture can be readily electrically interconnected to the next ("daisy chained"). After electrical connections are made, splice box lids, e.g. 82, are put in place and secured to the splice box, e.g. 43, by fasteners, e.g. 83. Low voltage or line voltage embodiments can be constructed in accordance with the above teachings.

Thus, those skilled in the art will appreciate that various adaptations and modifications of the just described preferred embodiment can be configured without departing from the scope of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.