Patent Publication Number: US-2021181539-A1

Title: Theatre light projector incorporating a plurality of light sources and improvements to blending the light output

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
     The present application is a continuation of and claims the priority of U.S. patent application Ser. No. 15/588,604 titled “THEATRE LIGHT PROJECTOR INCORPORATING A PLURALITY OF LIGHT SOURCES AND IMPROVEMENTS TO BLENDING THE LIGHT OUTPUT”, filed on May 6, 2017. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to improved light projectors. 
     BACKGROUND OF THE INVENTION 
     Theatre light projectors are often used to light theatrical stages or entertainers. Known light projectors can be comprised of a plurality of light sources where the plurality of light sources are comprised of a plurality of light emitting diodes (LEDs) as described in my U.S. Pat. RE44,903. Known light projectors that are comprised of a plurality of light sources typically may have an output lens assigned to each light source that are not seamlessly integrated so that they look more like one central light source. The lack of an apparent seamless integration of the output lenses of the known light projectors can be referred to in the theatrical industry as a “fly eye” type of light projector. 
     For example the SolaWash (trademarked) nineteen LED light projector as sold by High End Systems (trademarked) of Austin, Tex., as shown at http://www.highend.com/productss/led/solawash is comprised of circular arrays of discrete lenses that are not seamlessly integrated. A further example of a known light projector with a plurality of light sources and lenses is the ColorSource(trademarked) Par as marketed by Electronic Theatre Controls of Middleton, Wis. and is found at https://www.etcconnect.com/WorkArea/DownloadAsset.aspx?id=10737484145 
     It is desirable to better integrate a plurality output lenses used by a light projector so that the light projector appears to an audience as an apparent single light source. 
     SUMMARY OF THE INVENTION 
     An improved theatre light projector having multiparameter attributes is disclosed. The light projector may include a plurality of light sources, a lens system comprised of a plurality of sectors, and a housing having an inner chamber. The lens system may have a first side and a second side. The plurality of light sources and the lens system operate to produce an improved blended light beam for the light projector with less undesirable artifacts than previously known. 
     In at least one embodiment, a theatre light projector is provided which includes a housing, a plurality of light sources, a first aperture device and a lens system. The lens system may be comprised of a first lens sector and a second lens sector. Each of the first lens sector and the second lens sector may have a positive spherical optical power. In at least one embodiment, the first lens sector has a first radii, and the second lens sector has a second radii, wherein the first radii and the second radii are substantially parallel to each other. 
     The first aperture device may be comprised of a first aperture and the first aperture may be comprised of a color filter. The first aperture device may be comprised of a first aperture device and the first aperture device may be comprised of a pattern. The plurality of light sources may be comprised of a first light source and a second light source and each of the first light source and the second light source may be comprised of a white solid state light source. The white solid state light source may be a light emitting diode. The white solid state light source may be a laser diode. 
     The plurality of light sources may include a first light source and a second light source; wherein the first light source has a first heatsink and the second light source has a second heatsink; wherein the first light source is configured to project a first light having a first light path having a direction; and wherein the first heatsink is comprised of an adjustment mechanism for altering the direction of the first light path. The heatsink adjustment mechanism may be comprised of a compression component. 
     The theatre light projector may further include an output aperture wherein at least one surface of the output aperture has a stable wetting coating. The stable wetting coating may be a silicone derivative nano coating. 
     In at least one embodiment a theatre light projector is provided comprising a housing, a plurality of light sources, a first aperture device and variable diffusion system; wherein the plurality of light sources is comprised of a first light source which is configured to project a first light in a first light path and further comprising a second light source which is configured to project a second light in a second light path. 
     The variable diffusion system may be comprised of a first diffusing substrate and a second diffusing substrate. The first diffusing substrate may be rotatable into a first state and a second state wherein in the first state the first diffusing substrate is substantially perpendicular to the first light path and wherein in the second state the first diffusing substrate is substantially parallel to the first light path; and wherein the second diffusing substrate is rotatable into a first state and a second state wherein in the first state the second diffusing substrate is substantially perpendicular to the first light path and wherein in the second state the second diffusing substrate is substantially parallel to the second light path. 
     In at least one embodiment, the first aperture device is comprised of a first aperture and the first aperture is comprised of a color filter. The first aperture device may be comprised of a first aperture device and the first aperture device may be comprised of a pattern. 
     In at least one embodiment, the plurality of light sources are comprised of a first light source and a second light source and each of the first light source and the second light source is a white light source. Each of the plurality of light sources may be a light emitting diode. 
     The theatre light projector may include an output aperture wherein at least one surface of the output aperture has a stable wetting coating. The stable wetting coating may be a silicone derivative nano coating. 
     The plurality of light sources may be comprised of a first light source and a second light source wherein the first light source has a first heatsink and the second light source has a second heatsink; wherein the first light source is configured to project a first light in a first light path; and wherein the first heatsink is comprised of an adjustment mechanism for altering a direction of the first light path. The heatsink adjustment mechanism may be comprised of a compression component. 
     In at least one embodiment, a theatre light projector is provided comprising a housing, a plurality of light sources, a first aperture device, a lens system and a output aperture. The plurality of light sources may be comprised of a first light source and a second light source. 
     The first light source may be a solid state white light source, and the second light source may be a second solid state white light source. The first aperture device may be comprised of a plurality of apertures, including a first aperture, a second aperture, and an output aperture; wherein the first aperture is comprised of a first color filter; wherein the second aperture is comprised of a second color filter; wherein the output aperture is comprised of a first surface and a second surface; and wherein at least the first surface has a stable wetting coating. The stable wetting coating may be a silicon derivative nano coating. 
     The lens system may be comprised of a plurality of pie shaped lens components. The diffusing system may be comprised of a plurality of rotatable diffusing substrates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a simplified diagram of light projector in accordance with an embodiment of the present invention; 
         FIG. 2A  shows a close up of a light emitting module for use with the light projector of  FIG. 1 ; 
         FIG. 2B  shows a side view of the light emitting module of  FIG. 2A , and an adjustment system; 
         FIG. 2C  shows a rear view of the light emitting module of  FIG. 2A  and the adjustment system of  FIG. 2B ; 
         FIG. 3  shows a frontal view of a lens system comprised of a plurality of segments for use with the light projector of  FIG. 1 ; 
         FIG. 4  shows a frontal view of a diffusion system comprised of a plurality of segments for use with the light projector of  FIG. 1 , in a first diffusing state; 
         FIG. 5  shows a frontal view of the diffusion system of  FIG. 4  comprised of a plurality of segments in a second non-diffusing state; 
         FIG. 6  shows a side view of an output aperture of the prior art; and 
         FIG. 7  shows a side view of an output aperture incorporating a stable wetting coating in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a simplified diagram of light projector  100  in accordance with an embodiment of the present invention. The light projector  100  has an external housing  7 . The light projector  100  is comprised of a plurality of light sources  1   a ,  2   a ,  3   a  and  4   a . Each of the light sources  1   a ,  2   a ,  3   a  and  4   a  may be comprised of a solid state light source such as a light emitting diode (LED) or a laser diode (LD). LED  1   a  is mounted to a heatsink  1 , LED  2   a  is mounted to a heatsink  2 , LED  3   a  is mounted to a heatsink  3  and LED  4   a  is mounted to a heatsink  4 . Heatsinks  1 ,  2 ,  3  and  4  may be aluminum or copper heatsinks and may also be comprised of fluid pipes as known in the art to remove heat from the LEDs  1   a ,  2   a ,  3   a , and  4   a.    
     LEDs (or solid state light source)  1   a ,  2   a ,  3   a , and  4   a  may be of any wavelength (color) including white full spectrum but preferably each of LEDs  1   a ,  2   a ,  3   a  and  4   a  is comprised of multiple dies, each die having a different wavelength and may include white full spectrum, so that each of LEDs  1   a ,  2   a ,  3   a , and  4   a  is comprised of multiple wavelengths and may include white full spectrum. 
     Dotted line  1   b  shows a light path of a projected light from LED  1   a . Dotted line  2   b  shows a light path of a projected light from LED  2   a . Dotted line  3   b  shows a light path of a projected light from the LED  3   a  and dotted line  4   b  shows a light path of a projected light from the LED  4   a.    
     An aperatured device  10  of the light projector  100  of  FIG. 1  is positioned to intersect the light paths  1   b ,  2   b ,  3   b , and  4   b , simultaneously as described in U.S Patent RE40,015 to Belliveau, which is incorporated by reference herein. As the aperture device  10  is rotated different apertures can intersect the light paths  1   b ,  2   b ,  3   b  and  4   b .  FIG. 1  shows light path  1   b  passes though aperture  11   a , light path  2   b  passes though aperture  12   a , light path  3   b  passes though aperture  13   a  and light path  4   b  passes though aperture  14   a . When the aperture device  10  is rotated (with any suitable means as known in the art) in the direction of arrow  16  light path  1   b  passes though aperture  11   b , light path  2   b  passes though aperture  12   b , light path  3   b  passes though aperture  13   b  and light path  4   b  passes though aperture  14   b . The apertures  11   a ,  12   a ,  13   a ,  14   a ,  11   b ,  12   b ,  13   b  and  14   b  may be through hole apertures or contain color filters to modify the final output wave lengths (or color) of the LEDs  1   a ,  2   a ,  3   a  and  4   a . Apertures  11   a ,  12   a ,  13   a ,  14   a ,  11   b ,  12   b ,  13   b  and  14   b  may contain patterns to project images similar to gobo wheels with multiple pattern apertures as known in the art, and as disclosed, for example, in U.S. Pat. No. 5,402,326 to Belliveau, which is incorporated by reference herein. 
     The aperture device  10  shown contains eight apertures for simplification. However more apertures can be provided. The apertures that contain patterns may have all the same patterns at the same time for light paths  1   b ,  2   b ,  3   b  and  4   b  or the apertures may have different patterns for each of the light paths  1   b ,  2   b ,  3   b  and  4   b . The light projector  100  of  FIG. 1  is comprised of one aperture device  10 , however multiple aperture devices can be provided. The aperture device  10  may also be comprised of four separate pattern wheels with one separate pattern wheel for each light path  1   b ,  2   b ,  3   b , and  4   b .  FIG. 1  shows a dashed line  50  that is the center axis of the light projector  100  for reference. The center  18  of filter of aperture device  10  is also shown in line with the center axis dashed line  50  for symmetry. 
     The light projector  100  of  FIG. 1  is comprised of a lens system  20 . The lens system  20  is comprised of four lens sectors  21 ,  22 ,  23  and  24 . Light path  1   b  passes though lens sector  21 , light path  2   b  passes though lens sector  22 , light path  3   b  passes though lens sector  23  and light path  4   b  passed though lens sector  24 . Each of lens sectors  21 ,  22 ,  23  and  24  has an optical power that is a positive spherical optical power created by a radial curvature. It is important to keep the spherical optical power of the lens sectors  21 ,  22 ,  23 , and  24  as this allows for imaging and focusing of projection patterns provided by the filter or pattern wheel  10  of  FIG. 1 . For clarity on the term sector, a sector by definition, in accordance with the present application, is substantially a shape that is enclosed between an arc and two radii at either end of the arc and sometimes referred to as a substantially pie shaped section or triangular section. A pie shaped section should have at least two substantially flat sides in order to create the improved blended light beam output The lens system  20  can be constructed of a polymer or glass and the sectors  21 ,  22 ,  23 , and  24  can be molded or ground and polished. The lens sectors  21 ,  22 ,  23  and  24  can alternatively be constructed of a polymer Fresnel lens material to lower weight. The lens system  20  can be constructed of four separate lens sectors  21 ,  22 ,  23  and  24  and then fixed together by any suitable means or the lens system  20  can be constructed or molded of one piece. It is preferable for the lens sectors  21 ,  22 ,  23 , and  24  to have their radii as close together as possible to create a seamlessly integrated output beam of light that does not have the “fly eye” look when an operator views the light output.  FIG. 1  shows the integrated output projected light  55  of the light projector  100  with the output projected light projecting in the direction of arrow  51  for light path  1   b , arrow  52  for light path  2   b , arrow  53  for light path  3   b  and arrow  54  for light path  4   b .  FIG. 3  for reference shows a frontal view of the lens system  20  along with lens sector  21  with associated radii  21   a  and  21   b , lens sector  22  with associated radii  22   a  and  22   b , lens sector  23  with associated radii  23   a  and  23   b  and lens sector  24  with associated radii  24   a  and  24   b.    
       FIG. 3  shows that lens sector  21  has radii  21   b  substantially parallel to radii  22   a  of sector  22 . Lens sector  22  has radii  22   b  substantially parallel to radii  23   a  of lens sector  23 . Lens sector  23  has radii  23   b  substantially parallel to radii  24   a  of lens sector  24 . Lens sector  24  has radii  24   b  substantially parallel to radii  21   a  of lens sector  21 . 
     The lens system  20  of  FIG. 1  can also traverse along the center axis  50  in the direction of arrows  25   a  and  25   b  by any suitable means as known in the art to obtain a variable focus in relation to the filter and/or pattern wheel  10 . 
       FIG. 1  shows a diffusion system  30  that includes four optically diffusing sectors  31 ,  32 ,  33  and  34 . Light path  1   b  passes though the diffusing sector  31 , light path  2   b  passes though the diffusing sector  32 , light path  3   b  passed though the diffusing sector  33 , and light path  4   b  passes though the diffusing sector  34 . 
       FIG. 4  shows a front view of the diffusion system  30  in a first state  30   r . In the state  30   r  the diffusing sectors  31 ,  32 ,  33  and  34  intersect light paths  1   b ,  2   b ,  3   b  and  4   b  perpendicularly, respectively. In the state of  30   r  the light paths  1   b ,  2   b ,  3   b  and  4   b  pass though the optical diffusion substrate of the diffusing sectors. The diffusing sectors  31 ,  32 ,  33  and  34  may be manufactured of ground glass or an optically diffusing polymer substrate material such as manufactured by Bright View Technologies (trademarked) of Durham N.C. Each of the diffusing sectors  31 ,  32 ,  33  and  34  may be rotated along a center axis. For  FIG. 4  diffusing sector  31  is rotatable about axis  31   c  in the direction of arrow  31   r , which is in a plane perpendicular to the plane shown in  FIG. 4 . The diffusing sector  32  is rotatable about axis  32   c  in the direction of arrow  32   r , which is in a plane perpendicular to the plane shown in  FIG. 4  The diffusing sector  33  is rotatable about axis  33   c  in the direction of arrow  33   r , which is in a plane perpendicular to the plane shown in  FIG. 4 . The diffusing sector  34  is rotatable about axis  34   c  in the direction of arrow  34   r , which is in a plane perpendicular to the plane shown in  FIG. 4 . 
       FIG. 5  shows the diffusion system  30  in a second state  30   p . In the stage  30   p  each of the four optically diffusing sectors  31 ,  32 ,  33  and  34  has been rotated about their center axis ninety degrees so that the edges of the diffusing sector substrates, and the planes of the diffusing sectors  31 ,  32 ,  33 , and  34 , are arranged parallel to the light paths  1   b ,  2   b ,  3   b , and  4   b .  FIG. 5  shows the edge  31   e  of the substrate of the optically diffusing sector  31 , the edge  32   e  of the substrate of the optically diffusing sector  32 , the edge  33   e  of the substrate of the optically diffusing sector  33  and the edge  34   e  of the substrate of the optically diffusing sector  34 . The diffusion system  30  of  FIG. 5  in state  30   p  allows the light paths  1   b ,  2   b ,  3   b , and  4   b  to effectively pass through the diffusion system  30  without substantially altering the light paths  1   b ,  2   b ,  3   b  or  4   b  with the diffusion optical property of the diffusing sectors  31 ,  32 ,  33  and  34 . The diffusing sectors  31 ,  32 ,  33 , and  34  can be rotated about their corresponding axes  31   c ,  32   c ,  33   c  and  34   c , respectively, by any suitable electro mechanical or manual means as known in the art. 
     The light projector  100  of  FIG. 1  shows an exiting aperture  40  that may be constructed of a clear glass or a polymer. U.S. Pat. No. 8,770,764 to Belliveau, incorporated by reference herein, describes a system for reducing theatrical air born haze for a light projector that accumulates on output lenses or exiting apertures. The theatrical air born haze is comprised of glycol or mineral oil fog particles that are commonly created by atomization of the liquid glycol or mineral oil by theatrical fog generating devices (fog machines). The glycol or mineral oil particles (referred to herein as theatrical fog particles) can each range in size from between twenty microns to below 0.1 micron. 
     Because there can be a temperature differential between the inner surface and the outer surface of the exiting aperture  40  theatrical haze can typically form condensate on the inner surface or outer surface of the output optics. When the theatrical fog condensation forms on the optics the output light can become defused by the light scattering properties of the theatrical haze condensate. U.S. Pat. No. 8,770,764, incorporated by reference, has been reduced to practice and works well, however the light projector  100  of  FIG. 1  can always benefit from a cost reduction. The defogging system as described in U.S. Pat. No. 8,770,764 is comprised of several components including electronic power supplies, wiring and power resistors on a circuit board that accumulate to an increased cost of the light projector  100  if the system described by U.S. Pat. No. 8,770,764 were to be employed. 
       FIG. 6  shows a prior art output aperture  38  without the benefit of the system described by U.S. Pat. No. 8,770,764. In a known light projector the output aperture  38  can have a surface  39   a  located on a side near the internal housing of the known light projector and opposite surface side  39   b  near the outside of the known light projector. Because the side  39   a  is usually operating in a higher ambient temperature, the side  39   b  is operating in cooler ambient temperature. This causes the accumulation of fog particles like those shown as  38   a ,  38   b ,  38   c ,  38   d ,  38   e , and  38   f  on the surface  39   b . The theatrical fog particles  38   a ,  38   b ,  38   c ,  38   d ,  38   e , and  38   f  are formed as raised droplets because the surface energy of the substrate that the output aperture  38  is comprised of is higher than that of the surface tension of the theatrical fog particle. The inventor has found that by increasing the surface energy of the surface  39   b  of the output aperture  38  can increase the wetting characteristics of the surface and therfore reduce the height of the raised theatrical fog droplets to reduce the unwanted scattering of light by the apparent haze. This is especially important when incorporating low energy apertures or lenses made from polymers like PMMA (polymethyl methacrylate) or polycarbonate. 
       FIG. 7  shows the output aperture  40  of the light projector  100  that may exhibit a positive or negative optical power. The output aperture  40  has a stable nano coating  42  applied to the surface  41   b  that increases the wetting characteristics of the light output aperture  40 . A stable coating  42  is defined as a coating that increases the wetting characteristics of the aperture  40  even after during frequent wetting and dewetting cycles. The stable nano coating  42  is able to substantially withstand cleaning by industrial and household glass cleaners as the light projector  100  is often used in dirty and dusty outdoor shows and the apertures can be coated with dust and dirt that require cleaning. 
     The stable nano coating  42  can be comprised of silicon derivative such as silicone dioxide, silanes or siloxanes or a polymer in a solvent that can then be dip coated, sprayed or flow coated onto the output aperture  40  onto the surface  41   b  and/or the surface  41   a  of the aperture of  FIG. 7  The stable nano coating  42  increases the surface energy of the surface  41   b  so that theatrical fog particles  43   a  and  43   b  easily wet the surface  41   b  in a sheeting out manner (the sheeting out is preferably substantially flat and the fog particles  43   a  and  43   b  are shown as an exaggerated curve for the case of observance in the drawing). 
       FIG. 2A  shows a frontal view of the heatsink  1  of  FIG. 1  of light projector  100 . Heatsink  1  is identical to or substantially the same as heatsinks  2 ,  3  and  4  of  FIG. 1  of light projector  100 . Heatsink  1  shows LED or light source  1   a  that may be the same type of LED or light source for LED  2   a ,  3   a  and  4   a  of  FIG. 1  of light projector  100 . 
       FIG. 2B  shows a side view of the heatsink  1  and LED or light source  1   a . The LED or light source  1   a  has an optical light pipe  1   x  that may be fixed to the light source  1   a  in any manner. The optical light pipe  1   x  is used to gather and homogenize the light emitted by the LED or light source  1   a . Each of LEDs or light sources  2   a ,  3   a , and  4   a  may also include a similar or identical optical light pipe, like optical light pipe  1   x . The heatsink  1  is fixed to a stable surface  7  such as the lamp housing  7  of  FIG. 1 . The heatsink  1  is fixed to the surface  7  by screw fasteners  9   a  and  9   c . Springs  9   s  and  9   t  (or a flexible component such as an elastomer) are used to provide compression positioning adjustment of the heatsink  1  in relation to the surface  7  as the fasteners  9   a  and  9   c  are loosened or tightened.  FIG. 2B  shows a rear view of the heatsink  1  under the surface  7  by dotted line. Four screw fasteners are shown  9   a ,  9   b  (which are the same at  9   a  and  9   b  of  FIG. 2A ) and  9   c  and  9   d . At least three of the fasteners of fasteners  9   a ,  9   b ,  9   c , and  9   d  provide compression positioning of the heatsink  1  that results in fine the tuning of the direction of the light path  2  through the light projector  100  of  FIG. 1 . The heat sinks  1 ,  2 ,  3  and  4  of  FIG. 1  are fitted with this fine tuning positioning of the direction of the light paths  1   b ,  2   b ,  3   b  and  4   b  respectively. The fine tuning of the direction of the light paths  1   b ,  2   b ,  3   b  and  4   b  allow a technician to obtain the correct alignment of the light paths  1   b ,  2   b ,  3   b  and  4   b  at the output integrated light  55  of light projector  100  for blended light beam output with less undesirable artifacts. 
     Although the invention has been described by reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. It is therefore intended to include within this patent all such changes and modifications as may reasonably and properly be included within the scope of the present invention&#39;s contribution to the art.