Abstract:
An multimodal variable beam angle washlight and dynamic color flower effect luminaire is described employing multi colored LED array and a collimating partial homoginizing light guide which rotates paired with a rotating multifaceted prism which can selectively engage the light beam and be rotated while engaged. and further paired with a diffusion arm and zoom lens which converts the fixture into a variable angle wash light.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to a method for providing special effects in luminaires, specifically to a method relating to providing single and multiple beams from a single luminaire. 
       BACKGROUND OF THE INVENTION 
       [0002]    Luminaires with automated and remotely controllable functionality are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs and other venues. A typical product will provide control over the functions of the luminaire allowing the operator to control the intensity and color of the light beam from the luminaire that is shining on the stage or in the studio. Many products also provide control over other parameters such as the position, focus, beam size, beam shape and beam pattern. In such products that contain light emitting diodes (LEDs) to produce the light output it is common to use more than one color of LEDs and to be able to adjust the intensity of each color separately such that the output, which comprises the combined mixed output of all LEDs, can be adjusted in color. For example, such a product may use red, green, blue, and white LEDs with separate intensity controls for each of the four types of LED. This allows the user to mix almost limitless combinations and to produce nearly any color they desire. 
         [0003]      FIG. 1  illustrates a typical multiparameter automated luminaire system  10 . These systems typically include a plurality of multiparameter automated luminaires  12  which typically each contain on-board a light source (not shown), light modulation devices, electric motors coupled to mechanical drives systems and control electronics (not shown). In addition to being connected to mains power either directly or through a power distribution system (not shown), each luminaire is connected is series or in parallel to data link  14  to one or more control desks  15 . The luminaire system  10  is typically controlled by an operator through the control desk  15 . 
         [0004]    Luminaires have been provided using non-LED light sources designed to produce a single narrow beam or a plurality of such beams. Such luminaires may use low etendue, HID light sources with a small arc gap in order to facilitate the production of tight, almost parallel light beams. U.S. patent application Ser. Nos. 14/042,758 and 14/042,759 provide examples of such a system. Single and multi-color LED sourced luminaires have also been produced with narrow beam capability using sophisticated collimation systems as, for example, disclosed in U.S. patent application Ser. No. 14/405,355. LEDs however are high etendue light sources by comparison with HID and it is difficult to produce multiple beam systems using LED light sources. 
         [0005]    There is a need for a method for producing and controlling a light beam or multiple light beams from an LED sourced luminaire to produce controllable lighting effects. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein: 
           [0007]      FIG. 1  illustrates a multiparameter automated luminaire lighting system; 
           [0008]      FIG. 2  illustrates the layout of embodiments of major components of a light engine of a luminaire generating a flower effect; 
           [0009]      FIG. 3  illustrates more detail of some of embodiments of the major components and layout of the light engine illustrated in  FIG. 2 ; 
           [0010]      FIG. 4  illustrates and embodiment of additional support structure for the light guide assembly; 
           [0011]      FIG. 5  illustrates an embodiment of a light guide without any supporting structure; 
           [0012]      FIG. 6  illustrates the layout of a luminaire utilizing an embodiment of the optical softening elements disengaged; 
           [0013]      FIG. 7  illustrates the layout of a luminaire utilizing an embodiment of the optical softening elements in an engaged position; 
           [0014]      FIG. 8  illustrates the layout of a luminaire utilizing an embodiment of the multiplying optical elements in an engaged position; 
           [0015]      FIG. 9  illustrates detail of an embodiment of the optical softening diffuser; 
           [0016]      FIG. 10  illustrates the articulation drive system for the lenses of the embodiments illustrated; and; 
           [0017]      FIG. 11  illustrates a complete luminaire used in a lighting system illustrated in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Preferred embodiments of the present invention are illustrated in the FIGURES, like numerals being used to refer to like and corresponding parts of the various drawings. 
         [0019]    The present invention generally relates to a method for providing special effects in luminaires, specifically to a method relating to providing single and multiple beams from a single luminaire. 
         [0020]      FIG. 2  illustrates the layout of embodiments of major components of a light engine of a luminaire generating a flower effect. Light emitting module  20  comprises a single LED or an array of LEDs, which may include a primary optic (not shown). Light emitting module  20  may contain a single color of LEDs or may contain multiple dies, each of which may be of common or differing colors. For example, in one embodiment light emitting module  20  may comprise one each of a Red, Green, Blue and White LED. In further embodiments Light emitting module  20  may comprise a single LED chip or package while in yet further embodiments Light emitting module  20  may comprise multiple LED chips or packages either under a single primary optic or each package with its own primary optic. In some embodiments these LED die(s) may be paired with optical lens element(s) as part of the LED light-emitting module. In a further embodiment light emitting module  20  may comprise more than four colors of LEDs. For example, seven colors may be used, one each of a Red, Green, Blue, White, Amber, Cyan, and Deep Blue/UV LED die. 
         [0021]    The light output from the LEDs in light emitting module  20  enters light guide optic  22  contained within protective sleeve  24 . Light guide  22  may be a device utilizing internal reflection so as to collect, homogenize and constrain and conduct the light to exit port  23 . Light guide  22  may be a hollow tube with a reflective inner surface such that light impinging into the entry port may be reflected multiple times along the tube before leaving at the exit port  23 . Light guide  22  may be a square tube, a hexagonal tube, a heptagonal tube, an octagonal tube, a circular tube, or a tube of any other cross section. In a further embodiment light guide  22  may be a solid rod constructed of glass, transparent plastic or other optically transparent material where the reflection of the incident light beam within the rod is due to “total internal reflection” (TIR) from the interface between the material of the rod and the surrounding air. The integrating rod may a square rod, a hexagonal rod, a heptagonal rod, an octagonal rod, a circular rod, or a rod of any other cross section. Light guide  22  whether solid or hollow, and with any number of sides, may have entry port  21  and exit port  23  that differ in cross sectional shape. For example, a square entry port  21  and an octagonal exit port  23 . Further light guide  22  may have sides which are tapered so that the entrance aperture is smaller than the exit aperture. The advantage of such a structure is that the divergence angle of light exiting the guide  22  at exit port  23  will be smaller than the divergence angle for light entering the guide. The combination of a smaller divergence angle from a larger aperture serves to conserve the etendue of the system. Thus a tapered guide  22  may provide similar functionality to a condensing optical system. In a preferred embodiment of the present invention light guide  22  has both a square entry port  21  and a square exit port  23 . For the desired flower reminiscent effect it is advantageous to use shapes with opposing sides and to have the same shape cross section along the length of the guide  22 . 
         [0022]    Light guide  22  may have an aspect ratio where its length is much greater than its diameter. The greater the ratio between length and diameter, the better the resultant mixing and homogenization will be. Guide  22  may be enclosed in a tube or sleeve  24  that provides mechanical protection against damage, scratches, and dust. In the preferred embodiment light integrating tube  22  is of such a length so as to collimate and direct but deliberately provide incomplete homogenization of the light coming from individual LEDs on light emitting module  20 . This incomplete homogenization may be advantageously utilized in the remainder of the optical system. Similarly, the exit port of light guide  22  is polished, rather than being diffused or textured, to maintain the incomplete homogenization of the input light beams. In one embodiment the beams are less than 50% homogenized such that individual beams or colors from separate LEDs are still clearly visible. 
         [0023]    Light guide  22  within its protective sleeve  24  is mounted such that it may be freely rotated along its long, optical, axis through gears  32  and motor (not shown) supported by bearing  66 . Rotating light guide  22  will cause the emitted light beams from exit port  23  to also rotate around the optical axis of the system. In fact, the light beam movement and rotation will be complex, as a function of the rotation of the input port of light guide  22  across the array of LEDs in fixed light emitting module  20  and the total internal reflection within the rotating light guide. Thus the light beams exiting the light guide  22  will present a complex and dynamic pattern of moving beams. Light guide  22  may be rotated in either direction and at any speed under control of the operator. 
         [0024]    With the invention in its basic form, the light from the exit port  23  of light guide  22  will be directed towards and through first lens  38  and second lens  40  that serve to further control the angle of the emitted light beam. First lens  38  and second lens  40  may be moved as a pair towards and away from light guide  22  in the direction along the optical axis of the system shown by line  41  In the position where first lens  38  and second lens  40  are at their furthest separation from the exit port  23  of light guide  22  the emitted light beam will have a narrow beam angle. In the position where first lens  38  and second lens  40  are at their closest separation from the exit port  23  of guide  22  the emitted light beam will have a wide beam angle. Intermediate positions of the lenses  38  and  40  with respect to exit port  23  of light guide  22  will provide intermediate beam angles. First lens  38  and second lens  40  may advantageously be configured as an achromatic pair so as to minimize chromatic aberration of the emitted light beam or beams. The system illustrated herein utilizes two lens elements to provide output beam control, first lens  38  and second lens  40 . The invention is however not so limited, and further embodiments may contain different numbers and types of lenses or other optical systems as well known in the art. In particular, further embodiments may utilize systems where the relationship of first lens  38  and second lens  40  is not fixed, and can alter. Lenses  38  and  40  may be meniscus lenses, plano convex lenses, bi-convex lenses, holographic lenses, aspheric lenses, or other lenses as well known in the art. Lenses  38  and  40  may be constructed of glass, transparent plastic or other optically transparent material as known in the art. 
         [0025]    With the layout as described the effect from the luminaire will be that of a complex pattern of a plurality of light beams created by the reflection of the individual beams from the LEDs in light emitting module within light guide  22 . As no diffusion or other homogenization is provided, these beams will remain in differing colors and patterns through projection lens system comprising first lens  38  and second lens  40 . As the light guide  22  is rotated, and first lens  38  and second lens  40  are moved towards and away from the exit port  23  of light guide  22 , the effect will be that of a flower or spreading pattern of beams that opens and closes as the lenses are moved. 
         [0026]    The beams in the optical flower effect thus created may be further enhanced by inserting prism  34  across the beam in between exit port  23  of light guide  22  and first lens  38 . Prism  34  may be rotated around the optical axis when in position across the light beam. Motors may connect to drive systems  36  and  37  to enable control of insertion/removal of prism  34  across the light beam and rotating prism  34 . In the embodiment illustrated prism  34  is shown with 3 facets, for example  35 , spaced symmetrically around the circumference of the prism, producing a tripling of the beam numbers. In practice the prism may be of any shape or design with any number, orientation, and shape of facets. Prism  34  may be constructed of glass, transparent plastic or other optically transparent material as known in the art. Prism  34  may further be formed as a holographic diffusion or diffraction pattern. 
         [0027]    As a further refinement to the optical system, diffuser arm  26  may be swung across the light beam proximate to exit port  23  of light guide  22 . Diffuser arm may contain a number of diffusers each of which may have different diffusion properties. In the embodiment illustrated diffuser arm  26  is fitted with first diffuser  28  and second diffuser  30 , however further embodiments may have differing numbers of diffusers. In operation diffuser arm  26  is rotated such that one of the diffusers  28  or  30  is positioned proximate to exit port  23  of light guide  22  and will serve to diffuse and homogenize the light beams emitting from exit port  23  before they pass into the remainder of the optical system. The diffuser serves to merge the light beams into a single beam and to increase the spread of the light beam. Differing strengths or properties of diffuser  28  or  30  may provide narrow or wide homogenized beams without the flower effect or for lower powered diffusers a softening of the flower effect. In this mode of operation First lens  38  and second lens  40  will continue to control the overall size of the homogenized beam. Similarly, prism  34  will continue to multiply and affect the homogenized beam. 
         [0028]      FIG. 3  illustrates more detail of some of embodiments of the major components and layout of the light engine illustrated in  FIG. 2 . More specifically, in  FIG. 3 , exit port  23  of light guide  22  and the means for moving diffuser  28  and  30  across that exit port can may more clearly be seen. 
         [0029]      FIG. 4  illustrates the light guide assembly including its support structure. Sub  FIGS. 4 a , 4 b , 4 c , and 4 d    show the assembly from fully exploded ( 4   a ) through fully assembled ( 4   d ) to aid comprehension of the structure. Light guide  22  with exit port  23  is inserted into sleeve  24 . Sleeve  24  has, as parts of its structure, bearing support surfaces  64  and  68 . Bearing support surfaces  64  and  68  engage with bearing assemblies  66  and  70  respectively. This allows sleeve  24  (and thus light guide  22 ) to rotate within bearing assemblies  66  and  70 . Also attached to sleeve  24  is gear  62  which meshes with gear  32  shown in  FIG. 6  that is in turn driven by motor  33 . The assembly formed by sleeve  24 , light guide  22 , bearings  66  and  70 , and gear  62 , is supported within holder  72  such that (as shown in  FIG. 4 d   ) light guide  22  protrudes from the base of holder  72  and aligns with light emitting module  20 . This assembly also serves to maintain a small separation between entry port  21  of light guide  22  and light emitting module  20  such that light transfer from light emitting module  20  and light guide  22  is maximized but the two surfaces do not touch. 
         [0030]    In further embodiments it is envisaged that light guide assemblies as shown in  FIG. 4  could be used in multiples or arrays within a single luminaire. For example, a square array of rotating light guide assemblies may be used where each light guide is positioned above its own light emitting module. In these embodiments a single motor may drive the rotation of multiple light drive assemblies. 
         [0031]      FIG. 5  illustrates an embodiment of a light guide  22  without its support structure. Light guide  22  contains input port  21  and exit port  23 . In the embodiment illustrated light guide  22  is tapered and has both a square entry port  21  and a square exit port  23 . 
         [0032]      FIG. 6  illustrates the layout of a luminaire utilizing an embodiment of the optical softening elements. This figure shows the same system as  FIG. 2  with further detail on the movement systems in an embodiment. Motor  33  provides the motion for rotating light guide  22  through drive system  32 , and motor  35  provides the motion for diffuser arm  26 . Similarly motor  39  is one of two motors (second not shown) that insert/remove and rotate prism  34  across the beam. Similar motors and drive systems as well known in the art provide the motion for first lens  38  and second lens  40  along the optical axis of the luminaire. Motors  33 ,  35 , and  39  may be stepper motors, servo motors, linear actuators, solenoids, DC motors, or other mechanisms as well known in the art. In the embodiment shown the motors operate through gear systems  32  or belt systems  36  and  37 . For example, motor  33  drives gear  32 . Other mechanisms for actuating the desired movement as are well known in the art are also contemplated. In the position illustrated in  FIG. 6  prism  34  is out of the light beam as are both diffuser  28  and diffuser  30 . In this position the undiffused light beam presents the flower effect previously described. 
         [0033]      FIG. 7  illustrates the layout of a luminaire utilizing an embodiment of the optical softening elements in an engaged position. This figure shows the same system as  FIG. 6 . In the position illustrated in  FIG. 7  prism  34  is out of the light beam however diffuser arm  26  has been rotated such that diffuser  30  is positioned across the exit port of the light guide. In this position the light beam is diffused by diffuser  30  and presents an homogenized beam without the flower effect. 
         [0034]      FIG. 8  illustrates the layout of a luminaire utilizing an embodiment of the multiplying optical elements in an engaged position. This figure shows the same system as  FIG. 6  and  FIG. 7 . In the position illustrated in  FIG. 8  prism  34  has been positioned across the light beam however diffuser arm  26  has been rotated such that both diffuser  28  and diffuser  30  are out of the light beam. In this position the undiffused light beam presents the flower effect multiplied or affected by prism  34 . Although just three combinations of positions of diffuser arm  26 , and prism  34  have been shown, in practice any combination of the optical elements is envisaged. 
         [0035]      FIG. 9  illustrates detail of an embodiment of the optical softening diffuser arm  26 . Diffuser arm  26  is shown in two positions in  FIG. 9 . In position A, diffuser arm  26  is positioned such that diffuser  30  is across exit port  23  (shown dashed as it is under the diffuser). Also illustrated is an optional feature of diffuser arm  26 . Diffuser  28  includes mask  29  which serves to constrain the light to a masked shape. Mask  29  is an opaque mask with a central open aperture with, in this case, an hexagonal shape. Mask  29  helps to constrain the projected beam into a more rounded, non square, shape. Mask  29  may be of any shape, not just the hexagon illustrated herein, including but not limited to circular, hexagonal, or octagonal. 
         [0036]    In position B, diffuser arm  26  is positioned such that diffuser  28  including mask  29  is across exit port  23  (shown dashed as it is under the diffuser). Diffusers  28  and  30  may offer differing amounts or types of diffusion producing different beam spreads in the output. Diffusers  28  and  30  may be patterned or molded glass, or plastic, or may be holographic diffusers or other diffuser types as well known in the art. Although two different diffusers  28  and  30  are shown here the invention is not so limited and any number of diffusers or homogenizers may be affixed and selected as part of diffuser arm  26 . 
         [0037]      FIG. 10  illustrates the articulation drive system for the lenses of the embodiments illustrated. First lens  38  and second lens  40  may be supported by lead screws  46  connected to motors  44 . Rotation of motors  44  will move first lens  38  and second lens  40  back and forth along the optical axis of the system as indicated by arrow  43 . Although a lead screw system is illustrated here, the invention is not so limited and other methods of moving the lenses such as belt systems, linear actuators, rack and pinion gears, and other methods well known in the art are envisaged. When the zoom lens module is down at closest position to the optical rod and prism the fixture is outputting maximum beam angle which is soft and diffused (wash light), when the zoom lens module is up at furthest position from the optical rod and prism the fixture is outputting minimum beam angle which is sharp and focused and projecting the shape of RGBW chip when a diffusor is inserted or array of RGBW chips (flower effect) if the diffusors are not engaging the light beam. The beam angle can also be varied between these extremes and further modified by engagement and disengagement of the prism. 
         [0038]      FIG. 11  illustrates the articulation drive system for the lenses of the embodiments illustrated In the system illustrated luminaire head  52  includes an optical system as previously described and is rotatably mounted within yoke  54  which, in turn, is rotatably mounted to top box  56 . Either or both of the rotatable attachments from  52  to  54  or  54  to  56  may be capable of continuous rotation where electrical connectivity is provided across the rotating joint through slip rings or other devices. 
         [0039]    While the disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as disclosed herein. The disclosure has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the disclosure.