Abstract:
A light is mounted on each one of a plurality of movable light supporting carts. The carts are moved along a predefined path. The lights can be energized to produce light beams as the carts move. Alternatively, the lights may remain off as the carts are controllably moved along the path to position each cart at a selected location along the path, and the lights energized after the carts are position. The carts, or selected carts, can be controllably moved at a selectably variable speed or speeds and/or in a selectably variable direction or directions while the lights are energized to produce the light beams. The lights themselves can be controllably moved with respect to their respective support carts, to controllably pan, tilt, swivel, etc. each light as the carts move, thereby facilitating production of a wide range of illumination effects.

Description:
TECHNICAL FIELD  
         [0001]    This invention provides a theatrical lighting system in which lights are movable during a performance to produce crowd-pleasing “light shows” and/or to controllably illuminate selected portions of a stage, theater, sports arena, etc.  
         BACKGROUND  
         [0002]    Indoor or outdoor events such as rock concerts, sporting events, Olympic games, theme parks, worlds&#39; fairs, theatrical performances, etc. often require illumination and may also include “light shows” in which a plurality of light sources are actuated for illumination purposes and/or to make a “visual statement” to entertain persons attending such events. Commonly for example, a variety of computer controlled laser light sources and/or strobe lights and/or search lights and/or theatrical lights produce sequences of moving and/or pulsating and/or variable color light beams and/or other lighting effects, often in synchronization with music and/or other sound effects.  
           [0003]    It is also conventional to illuminate selected portions of a stage, arena, etc. by aiming one or more lights at such portions. This is typically accomplished by a skilled operator who manually actuates controls coupled to servo motors in order to energize (i.e. turn “on” so as to produce illumination), de-energize (i.e. turn “off”), aim, swivel, pan, tilt, etc. one or more lights, with additional controls being provided for varying the lights&#39; brightness, applying color filters to the lights, etc.  
           [0004]    Prior art lighting systems of the foregoing types utilize lights which typically remain fixed in position during the performance or event. That is, apart from servo-actuated aiming, swivelling, panning, tilting, etc. of individual lights, none of the lights are physically movable from one location to another location while the lights are operated to produce the light show, illuminate selected stage portions, etc.  
           [0005]    The present invention provides a theatrical lighting system in which lights are movable between different physical locations while the lights are operated to create unique light show effects, illuminate selected stage portions, etc.  
         SUMMARY OF INVENTION  
         [0006]    In accordance with the invention, a light is mounted on each one of a plurality of movable light supporting carts. The light-bearing carts are moved along a predefined path. The lights can be energized to produce light beams as the carts move. Alternatively, the lights may remain de-energized as the carts are controllably moved along the path to position each cart at a selected location along the path, and the lights energized after the carts are in position. The carts, or selected carts, can be controllably moved at a selectably variable speed or speeds and/or in a selectably variable direction or directions while the lights are energized to produce the light beams.  
           [0007]    The lights themselves can be controllably moved with respect to their respective support carts, to controllably aim, pan, tilt, swivel, etc. each light as the carts move, thereby facilitating production of a wide range of illumination effects. If desired, the lights, or selected lights, can be controllably moved with respect to the carts to aim the lights at a selected focal point, and to maintain such aim if the focal point moves. The lights can also be individually controlled to selectably vary the color of the light beam produced by each light. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]    [0008]FIG. 1 is a top plan view of a theatrical lighting system in accordance with one embodiment of the invention.  
         [0009]    [0009]FIG. 2 is an oblique isometric schematic illustration of a portion of the FIG. 1 theatrical lighting system, showing the light beams projected when the lights are deployed as shown in FIG. 1.  
         [0010]    [0010]FIG. 3 is a partial side elevation sectional view of the FIG. 1 system.  
         [0011]    [0011]FIGS. 4A, 4B,  4 C and  4 D respectively schematically depict different arrangements of moveable lights in accordance with the invention.  
         [0012]    FIGS.  5 A- 5 N respectively schematically depict different light show effects and stage illumination effects producible by theatrical lighting systems in accordance with the invention.  
         [0013]    [0013]FIG. 6 is a partially sectioned side elevation view of one embodiment of a track and self-propelled cart for moving lights in accordance with the invention. 
     
    
     DESCRIPTION  
       [0014]    [0014]FIG. 1 depicts two separate tracks  10 ,  12  along which lights are movable in accordance with the invention. Track  10  is configured to form a closed loop path enclosing region  11  which may fully or partially contain an audience and/or a “set” for an event, performance or for filming, etc. Track  10  happens to be circular in this embodiment, but could have any other desired path shape amenable to movement of lights, as hereinafter explained. Track  12  is in the form of an arc segment path having distinct end points with suitable end stops  13 . Track  12  can have any desired path shape amenable to movement of lights as hereinafter explained.  
         [0015]    A plurality of “movable light supports” such as wheeled carts  14 A,  14 B,  14 C,  14 D,  14 E or other suitable vehicular mechanisms, are mounted on tracks  10 ,  12 . One or more lights  16  are mounted on each cart. Lights  16  may for example be automated indoor/outdoor xenon search lights of the type manufactured by Space Canon vH of Fubine, Italy. Such lights incorporate computers and stepper motors which can be electrically coupled to suitable controllers to facilitate automated energizing (i.e. to produce illumination by turning the light “on”), de-energizing (i.e. turning “off”), aiming, panning, tilting, swivelling, dimming, beam convergence, beam divergence, etc. of the individual light.  
         [0016]    Light-supporting carts  14 A,  14 B,  14 C,  14 D,  14 E are moveable along tracks  10 ,  12  as hereinafter explained, with each of lights  16  being fully operational and controllable during such movement. For example, the five carts  14 A shown on the upper half of track  10  as viewed in FIG. 1 have been moved to separate carts  14 A at equal distances from one another along the upper half of track  10 . By contrast, the five carts  14 B shown on the lower half of track  10  as viewed in FIG. 1 have been moved to cluster carts  14 B together in the lowermost part of track  10 , with two carts  14 C having been moved to space them farther apart and to the left of the  14 B five-cart cluster; and, another two carts  14 C having been moved to space them farther apart and to the right of the  14 B five-cart cluster. Similarly, the central four carts  14 D depicted on track  12  have been moved to cluster carts  14 D together in the lowermost part of track  12  as viewed in FIG. 1, with the remaining two carts  14 E positioned farther away on either side of carts  14 D. Besides moving each light-bearing cart, one may also independently tilt, pan, swivel, rotate, etc. each of lights  16  by suitably actuating the aforementioned computers and stepper motors incorporated in each one of lights  16 .  
         [0017]    [0017]FIGS. 2 and 3 depict an example of one of many different lighting arrangements which can be produced with the aid of the invention. For simplification, track  12  is not shown in FIG. 2, but it is shown in FIG. 3. FIG. 3 also illustrates the fact that track  10 , track  12  and stage  18  may at different heights. For example, circular track  10  may be formed around the circumference of a stadium above the audience seating and playing/performance areas.  
         [0018]    [0018]FIGS. 2 and 3 correspond to the situation in which carts  14 A,  14 B and  14 C are positioned on track  10  as described above in relation to FIG. 1. More particularly, lights  16  on the five equally spaced carts  14 A on the upper, central portion of track  10  (as viewed in FIG. 1) are actuated via their on-board computers and stepper motors to point each of those five lights at a steep upward angle to produce “backdrop” light rays  20  which may converge at a point above a notional focal point “F” on stage  18 . Lights  16  on the remaining carts  14 B,  14 C on track  10  are energized to aim each of those lights at focal point F, producing stage illumination light rays  22  as shown in FIGS. 1, 2 and  3 .  
         [0019]    [0019]FIG. 3 depicts backdrop rays  20  and stage illumination rays  22  using solid lines. FIG. 3 also depicts, using dashed lines, additional converging light rays  24 , and various other light rays  25 , to illustrate the fact that each one of lights  16  can produce different light rays by suitably actuating their on-board computers and stepper motors to pan, tilt, swivel, etc. any one of lights  16  with respect to the cart on which that light is mounted. Some of the FIG. 3 light beams are represented by double-headed arrows which project in two axially opposed directions from one of lights  16 . This can be achieved by mounting two lights back-to-back on a single cart, with provision being made for independently controlling each of the two lights.  
         [0020]    Focal point F may be stationary or movable as indicated by arrows  19  in FIG. 1. A control system  26  (FIG. 3) can be provided to actuate the on-board computers and stepper motors on any selected ones of lights  16  to cause those lights to pan, tilt, swivel, change intensity, change color, etc. (whether or not the carts on which such lights are mounted are moving), to cause such lights to track focal point F, or to project light rays in any other desired manner. Tracking of focal point F can be accomplished, for example, by mounting a transponder  28  in a fixed location on stage  18 . Alternatively, transponder  28  can be sewn into a garment or provided in a bracelet, pendant, necklace or other implement wearable by a performer  30 . In either case, control system  26  monitors the location of transponder  28  in well known fashion by means of electronic signals exchanged via wireless communication between control system  26  and transponder  28 .  
         [0021]    In addition to controllably actuating the on-board computers and stepper motors on lights  16 , control system  26  also controllably actuates carts  14 A,  14 B,  14 C,  14 D,  14 E as hereinafter explained. Each cart can be moved backwards or forwards along tracks  10 ,  12  at a selected speed, under programmed and/or manual control by control system  26 . Control system  26  maintains a database containing information representative of the current location of each cart and the current orientation of each one of lights  16  with respect to such light&#39;s cart, thus enabling control system  26  to produce signals to move selected carts and/or actuate the on-board computers and stepper motors on selected ones of lights  16  to keep those lights aimed at focal point F, or to project light rays in any other desired manner. Focal point F can move if transponder  28  is worn by a performer as aforesaid. A plurality of transponders can be provided at different locations on stage  18 , or at other positions throughout the facility with which the theatrical lighting system is associated if control system  26  is suitably programmed to cause selected ones of lights  16  to track a selected one of the plurality of transponders.  
         [0022]    As an alternative to transponder-based control of lights  16 , a single “master” one of lights  16  can be aimed in conventional fashion by an operator using a joystick or other suitable device coupled to the master light&#39;s on-board computer and stepper motor, with any selected ones of the remaining lights  16  being “slaved” to the master light such that the master and all of the slave lights are simultaneously panned, tilted, swivelled, etc. as the operator actuates the joystick control device.  
         [0023]    FIGS.  4 A- 4 D schematically depict different arrangements of moveable lights in accordance with the invention. White circles “∘” represent lights  16  which are “on”. Black circles “” represent lights  16  which are “off” (i.e. not energized to produce illumination; lights  16  can be moved whether they are on or off). For simplification, the carts which support each light  16  are not shown in FIGS.  4 A- 4 D.  
         [0024]    [0024]FIG. 4A depicts an embodiment of the invention incorporating two straight, parallel tracks  15 ,  15 A. For simplification, track  15 A is represented only schematically as a dashed line. A single transponder or otherwise-defined focal point F which can move as indicated by arrows  19  is shown. The FIG. 4A embodiment is, for example, representative of a movable lighting arrangement for a football field, track, or other area which can be illuminated by means of spaced apart, straight parallel tracks along which carts bearing lights  16  can be moved. Lights  16  can be moved along tracks  15 ,  15 A to group or cluster the lights to illuminate focal point F, as is indicated in FIG. 4A by the clustered white circles “∘” representing lights which are “on”.  
         [0025]    [0025]FIG. 4B corresponds to FIGS. 1, 2 and  3  except that FIG. 4B shows track  12  inside track  10 . The dashed outline bearing reference numeral  18  indicates that a conventional fixed “stage” is unnecessary: the invention facilitates movement and aiming of lights  16  such that any portion of the facility associated with the theatrical lighting system may be illuminated to serve as a stage. The dashed outline bearing reference numeral  28  reflects the fact that one or more transponders may be associated with stage  18  and/or associated with (i.e. worn by) one or more performers, who need not necessarily remain on the “stage”. That is, transponders  28  need not necessarily result in illumination of stage  18 , but may be positioned to illuminate any desired feature or object in the facility associated with the theatrical lighting system.  
         [0026]    [0026]FIG. 4C depicts another embodiment of the invention incorporating a closed oval track  80  within two additional tracks  82 ,  84 . The dashed outline portions of tracks  82 ,  84  indicate that those tracks may be either closed loops or arc segments, as desired. An additional linear track  15  is also depicted in FIG. 4C. Light-bearing carts can be mounted on and moved along each of tracks  80 - 86  as previously explained. The dashed outlines bearing reference numeral  28  illustrate the fact that each transponder may be associated with different lights. For example, in FIG. 4C, some lights  16  have been moved to cluster them together on the lower right portions of tracks  80 ,  82 ,  84  to better enable those lights to be focused upon and illuminate the right hand transponder  28 ; whereas other lights  16  have been moved to cluster them together on the lower left portions of tracks  80 ,  82 ,  84  to better enable those lights to be focused upon and illuminate the left hand transponder  28 .  
         [0027]    [0027]FIG. 4D depicts another embodiment of the invention incorporating an irregular shaped, closed path track  90 ; and two irregular shaped, open-ended tracks  92 ,  93  along either of which light-bearing carts can be moved to associate lights  16  with any one or more of performance focal areas F 1 , F 2 , F 3  or F 4 . Shunt tracks  94 ,  96 ,  98  are provided for storage of unused lights  100 . More particularly, shunt track  94  is coupled to track  90  to enable lights to be moved off track  90  onto shunt track  94  for storage, repair, etc.; and/or to enable additional lights to be moved off shunt track  94  and into service on track  90 . Shunt track  96  is couplable to track  92  to enable lights to be moved off track  92  onto shunt track  96  for storage, repair, etc.; and/or to enable additional lights to be moved off shunt track  96  and into service on track  92 . Shunt track  98  is coupled to track  93  and further couplable to track  92  as indicated by dashed line track segment  112  to enable lights to be moved off either of tracks  92 ,  93  onto shunt track  98  for storage, repair, etc.; and/or to enable additional lights to be moved off shunt track  98  and into service on either of tracks  92 ,  93 . Dashed line track segments  110 ,  112  can be included to provide a closed loop track analogous to tracks  10 ,  12  described above with reference to FIGS. 1, 2 and  3 .  
         [0028]    FIGS.  5 A- 5 N schematically depict different light show effects and/or stage illumination effects producible by theatrical lighting systems in accordance with the invention. White circles “∘” represent lights  16  which are “on”. Black circles “” represent lights  16  which are “off”. For simplification, the carts which support each light  16  are not shown in FIGS.  5 A- 5 N.  
         [0029]    [0029]FIGS. 5A, 5B are respectively oblique top and top plan views showing a plurality of parallel, vertical light beams (represented by the vertical arrows in FIG. 4A) produced by clustering together on track  10  a plurality of carts bearing lights  16  and actuating the lights&#39; on-board computers and stepper motors to aim each light vertically. Arcuate, double-headed arrow R indicates that the carts can be caused to move in either direction along track  10  while the lights are energized to produce a moving light beam lighting effect.  
         [0030]    [0030]FIGS. 5C, 5D are respectively oblique bottom and top plan views showing a “funnel” lighting effect producible by equidistantly spacing on track  10  a plurality of carts bearing lights  16  and actuating the on-board computers and stepper motors on each of lights  16  to tilt each light such that the resultant light beams project radially outwardly and away from one another and at an angle relative to a notional plane containing track  10 . The light beams are represented by straight, double-headed arrows in FIGS. 6C, 6D indicating usage of double-headed lights which project light in two axially opposed directions. Specifically, each arrow has a solid line portion to indicate light beam projection beneath the notional plane containing track  10 , and a dashed line portion to indicate light beam projection above the notional plane containing track  10 . Arcuate, double-headed arrow R again indicates that the carts can be caused to move in either direction along track  10  while the lights are energized to produce a moving funnel lighting effect.  
         [0031]    [0031]FIGS. 5E, 5F are respectively oblique top and top plan views showing a “conical” lighting effect producible by equidistantly spacing on track  10  a plurality of carts bearing single-headed lights  16  and actuating the lights&#39; on-board computers and stepper motors to aim each light inwardly and upwardly at the same angle relative to the notional plane containing track  10 . This produces a plurality of light beams (represented by straight arrows) which intersect at an apex point above the notional plane containing track  10 . The conical lighting effect can be enhanced by further actuating the lights&#39; on-board computers and stepper motors to vary the displacement between the apex point and the notional plane containing track  10 . If desired, an inverted conical lighting effect (not shown) can be produced by actuating the lights&#39; onboard computers and stepper motors to aim the lights at an apex point below the notional plane containing track  10 . A moving, diverging/converging conical lighting effect can be produced by actuating the lights&#39; on-board computers and stepper motors to continuously sweep the apex point through a range of positions above and below the notional plane containing track  10 . Arcuate, double-headed arrow R again indicates that the carts can be caused to move in either direction along track  10  while the lights are energized and actuated to produce a variety of moving conical lighting effects.  
         [0032]    [0032]FIGS. 5G, 5H are respectively oblique bottom and top plan views showing a “searchlight” lighting effect producible by equidistantly spacing on track  10  a plurality of carts bearing lights  16  and actuating the lights&#39; on-board computers and stepper motors to aim each light in the same direction, such that the projected light beams remain parallel to one another. The light beams are represented by straight, double-headed arrows in FIG. 5G indicating usage of double-headed lights which project light in two axially opposed directions. Specifically, each arrow has a solid line portion to indicate light beam projection beneath the notional plane containing track  10 , and a dashed line portion to indicate light beam projection above the notional plane containing track  10 . The lighting effect can be enhanced by further actuating the lights&#39; on-board computers and stepper motors to tilt, swivel, rotate, etc. each light while maintaining the light beams parallel to one another. Arcuate, double-headed arrow R again indicates that the carts can be caused to move in either direction along track  10  while the lights are energized and actuated to produce a variety of moving searchlight lighting effects. Alternatively, instead of maintaining the light beams parallel to one another, one could actuate the lights&#39; on-board computers and stepper motors to aim each light at a selected azimuth and elevation relative to the immediately adjacent and preceding light, such that when viewed from a selected direction, the projected light beams appear to radiate from a common origin with fixed angular spacing between adjacent light beams (not shown).  
         [0033]    [0033]FIGS. 5I, 5J are respectively oblique top and top plan views showing a “nodding” lighting effect producible by clustering two separate groups  16 C,  16 D of lights on opposite sides of track  10 , and actuating the lights&#39; on-board computers and stepper motors to produce light beams (represented by straight arrows in FIGS. 5I and 5J) which project radially outwardly and away from track  10 . The lighting effect can be enhanced by further actuating the lights&#39; on-board computers and stepper motors to alternately sweep the light beams in unison (or sequentially) upwardly and downwardly as indicated by double-headed arrow W; or, to alternately sweep each 1st, 3rd, etc. light upwardly while simultaneously sweeping each 2nd, 4th, etc. light downwardly, etc. Arcuate, double-headed arrow R again indicates that the carts can be caused to move in either direction along track  10  while the lights are energized and actuated to produce a variety of moving nodding lighting effects.  
         [0034]    [0034]FIGS. 5K, 5L are respectively oblique top and top plan views showing a “cross over” lighting effect producible by clustering two separate groups  16 A,  16 B of lights on opposite sides of track  10 , and actuating the lights&#39; on-board computers and stepper motors to produce light beams (represented by straight arrows in FIGS. 5K and 5L) which are parallel to one another and parallel to or at any selected angle relative to the notional plane containing track  10 . Arcuate, double-headed arrows “S” indicate that the lights&#39; on-board computers and stepper motors can be actuated to sweep each group of light beams through any desired arc, while maintaining each group of light beams parallel to one another. Arcuate, double-headed arrow R again indicates that the carts can be caused to move in either direction along track  10  while the lights are energized and actuated to produce a moving, sweeping cross over lighting effect.  
         [0035]    [0035]FIGS. 5M, 5N are respectively oblique top and top plan views showing a “pulsating” lighting effect whereby every other light along track  10  is alternately, momentarily switched on and off. The black circles “” on track  10  in FIGS. 5M, 5N represent lights which are momentarily “off”, and the white circles “∘” represent lights which are momentarily “on”. The solid line vertical arrows in FIG. 5M represent light beams projected by lights which are “on”, and the dashed arrows represent light beams which are momentarily “off”. Arcuate, double-headed arrow R again indicates that the carts can be caused to move in either direction along track  10  while the lights are energized and actuated to produce a moving, pulsating lighting effect as the light beams are momentarily switched on and off as aforesaid. Any selected combination of lights can be pulsated on and off as aforesaid; and, such pulsation may be combined with any other lighting effect producible in accordance with the invention.  
         [0036]    [0036]FIG. 6 shows how cart  14 ′ with light  16  mounted thereon can be positioned for movement along track  10 . Track  10  comprises structural members  30  which are welded together to form a rigid framework supporting rails  32 . If desired, the framework can be configured to elevate one of rails  32  with respect to the other rail, for example to counteract centrifugal forces generated as cart  14 ′ moves along track  10  (in the case of a circular or other arcuate track shape). Cart  14 ′ incorporates a platform  34  on which light  16  is fixedly mounted. Wheels  36  are rotatably supported on axles  38  which are in turn fixed on opposed undersides of cart  14 ′ in suitable positions for rotatable engagement of wheels  36  with tracks  32 .  
         [0037]    A power supply  40  is provided at any suitable location alongside track  10 . Power conductor  42  is electrically coupled between power supply  40  and power rail  44 , which extends the full length of track  10  between and parallel to rails  32 . Power rail  44  is supported by brackets  46  which are in turn fastened to support members  30 . Cart power conductor  48  protrudes downwardly through aperture  50  in cart platform  34  and is electrically coupled between light  16  and wiper  52 . Bracket  54  fixed to the underside of platform  34  extends beneath platform  34  and between wheels  36 . Wiper  52  is pivotally coupled to the lower end of bracket  54  via spring-loaded swivel mount  56  which biases wiper  52  upwardly against the underside of power rail  44  to maintain continuous electrical contact between power conductors  58  on power rail  44  and slidably mating power contacts  60  provided on wiper  52 .  
         [0038]    Another power conductor  62  is electrically coupled between conductor  48  and a “drive mechanism” such as drive motor  64  which is fixed to the side of platform  34 . The drive shaft  66  of motor  64  is drivingly coupled to wheel  68  which rotates against a traction surface  70  provided on one of members  30  and extending the entire length of track  10 . In addition to providing power for operation of light  16  and drive motor  64 , the above-described power coupling mechanism can also be used to electrically couple control signals between control system  26  (FIG. 3) and light  16 &#39;s on-board computer and stepper motor.  
         [0039]    As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example, instead of configuring motor  64  (FIG. 6) to drivingly rotate wheel  68  against traction surface  70 , one could alternatively couple drive motor  64  to either or both of axles  38  to directly drive wheels  36  along rails  32 . As another example, rails  32  and wheels  36  could have geared surfaces to facilitate more precise positioning of carts  14 ′ with respect to tracks  10 ,  12 . As a further example, any of lights  16  may be equipped with dual 180° opposed light emitting modules capable of emitting two longitudinally opposed light rays, as previously explained with reference to FIG. 3. As another example, brakes (not shown) can be coupled to wheels  36  for controllable actuation by control system  26  in order to stop any selected cart  14 ′ at a particular point on tracks  10 ,  12 . Such brakes can be configured to remain actuated in the absence of applied electrical power as a safety feature to prevent unintended movement of carts  14 ′ in the event of a power failure. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.