High intensity lighting projectors

Abstract

A high intensity light projector for stage, architectural and similar applications includes a controllable image quality projection gate providing advanced visual effects. The projection gate, capable of selectively scattering or transmitting incident light, may be constructed of an array of scattering liquid crystal material in combination with infrared and ultraviolet reduction means which provide in the high intensity beam, a stable thermal environment by minimizing the absorption of light by the projection gate. Additional thermal efficiency is provided by supplemental cooling means. Color control is also provided in the form of dichroic filter wheels forming cooperating adjustable low, high and band width filters including saturation control. A color measuring feedback sensor is also provided. An intensity measuring feedback sensor controls a spatially-modulated, variable-density, reflectively-coated dimming wheel. A programmable gobo system has provisions for gobo selection, orientation, and rotation.

What is claimed is:  
     
         1 . A light projection system for lighting applications having one or more light projectors which include image forming means, said one or more projectors comprising: 
 (1) a light beam source for generating a beam having an intensity suitable for lighting applications;    (2) a projection gate located to modulate said beam and having an addressable array of light scattering liquid crystal pixels in an essentially non-absorptive optical environment, said pixels being capable of assuming transparent and opaque states;    (3) a heat control system for protecting said array of liquid crystals from the heat generated by said beam; and    (4) a source of image control signals connected to said array to control the states of said pixels to vary the image projected by said beam.    
     
     
         2 . An image projection system comprising: 
 (1) a high intensity light beam source for generating a beam;    (2) a beam modulation system including an addressable array of light scattering liquid crystal pixels capable of assuming transparent and opaque states and positioned to modulate unpolarized light transmitted in said beam;    (3) a heat control system for said array including a heat sink in thermally conductive relationship with said array; and    (4) a source of image control signals connected to said array to control the transmission states of said pixels to thereby vary the image projected by said beam.    
     
     
         3 . A system according to claims  1  or  2  including beam color control means for controlling the color of the beam modulated by said liquid crystal array.  
     
     
         4 . A system according to claims  1  or  2  in which said heat control system includes a liquid cell.  
     
     
         5 . A system according to claims  1  or  2  in which said system includes means for diverting radiant energy in the infrared range or the ultraviolet range from said array.  
     
     
         6 . A system according to claims  1  or  2  in which said system includes a dielectric interference filter having dichroic properties for protecting said array from potentially damaging radiant energy.  
     
     
         7 . A system according to  claim 1  including an essentially sealed housing enclosing said light projectors.  
     
     
         8 . A system according to claims  1  or  2  including a hot mirror positioned between said beam source and said array.  
     
     
         9 . A system according to claims  1  or  2  in which at least certain of said liquid crystal pixels comprise nematic liquid crystal materials dispersed in a polymer matrix.  
     
     
         10 . A system according to claims  1  or  2  including a folded optical system to reverse the direction of said beam.  
     
     
         11 . A system according to claims  1  or  2  in which said heat control means includes a liquid circulation system.  
     
     
         12 . A system according to claims  1  or  2  in which said liquid crystal pixels comprise liquid crystal material selected from the group comprising polymer dispersed liquid crystals, nematic curvilinear aligned phase liquid crystals, liquid crystal polymer composites, and polymer network liquid crystals.  
     
     
         13 . A system according to claims  1  or  2  in which said heat control system does not depend on forced air circulation whereby silent operation is achieved.  
     
     
         14 . A system according to claims  1  or  2  including a programmable gobo control system for imposing additional modulation of said beam.  
     
     
         15 . A system according to claims  1  or  2  in which the transparency of said liquid crystal pixels can be adjusted over a range of values to provide gray scale effects.  
     
     
         16 . A system according to claims  1  or  2  including (1) a primary color generator for filtering said beam to repetitively produce three primary colors in succession for illuminating said array, (2) means for controlling said liquid crystal pixels to produce video images corresponding to each of said primary colors in synchronism with the illumination of said array with said primary colors, whereby said beam is modulated with said colored video images.  
     
     
         17 . A system according to claims  1  or  2  including: 
 (1) a carrier for supporting a plurality of gobos;  
 (2) means for controlling said carrier to position one of said gobos in said beam; and  
 (3) means for varying the angular orientation, velocity, and direction of a selected gobo, whereby the generated beam pattern can be adjusted by both gobo pattern selection and orientation of the selected gobo.  
 
     
     
         18 . A system according to claims  1  or  2  in which said array includes an active matrix coupled to said source of image control signals.  
     
     
         19 . A system according to claims  1  or  2  including a color control system for adjusting the color of said beam, said color control system including a plurality of cooperating dichroic filter elements, each of said elements having adjustable filter characteristics capable of selective positioning in said beam.  
     
     
         20 . A light projection system for lighting applications having at least one light projector which includes beam color control means, said projector comprising: 
 (1) a light beam source for generating a beam having an intensity suitable for lighting applications;    (2) a set of color filter elements movable in position relative to said beam;    (3) certain of said color filter elements comprising continuously variable dichroic filtering materials such that beam hue is adjustable according to the position of said elements.    
     
     
         21 . A system according to  claim 20  in which at least one of said color filter elements is capable of movement in two directions relative to the beam axis to provide both hue and saturation control.  
     
     
         22 . A system according to  claim 20  in which said color filter elements constitute variable color band width, variable color center filters.  
     
     
         23 . A system according to  claim 20  in which said color filter elements exhibit variable dichroic properties in a rotary direction so that transmission of one band of wavelengths and reflection of others is continuously selectable.  
     
     
         24 . A system according to  claim 20  in which certain of said color filters elements are in a subtractive relationship.  
     
     
         25 . A system according to  claim 20  including a color control system for moving said filter elements, said control system including color responsive feedback means for sensing beam color.  
     
     
         26 . A system according to  claim 20  in which said filter elements are essentially devoid of elemental metallic components.  
     
     
         27 . A system according to  claim 20  in which said filtering materials include a plurality of multi-layer dielectric thin films having different optical properties.  
     
     
         28 . A system according to  claim 20  in which said filtering materials have spatially variable density to facilitate saturation control.  
     
     
         29 . A system according to  claim 20  in which said filtering materials include a plurality of dielectric films which are continuously graduated with differing thickness, density or refractive index spatially distributed to produce continuously variable hue and saturation.  
     
     
         30 . A light projection system for entertainment lighting having at least one light projector which includes beam color control means, said projector comprising: 
 (1) a light beam source for generating a beam having an intensity for entertainment lighting;    (2) a controllable color filter for adjusting the color of said beam;    (3) a spectrum-indicating feedback device responsive to the adjusted beam and having an output indicative of which of a plurality of colors characterize the adjusted beam; and    (4) a controller responsive to said feedback device and arranged for controlling said filter.    
     
     
         31 . A system according to  claim 30  in which said feedback device includes a dichroic filter having a plurality of wavelength-indicating outputs, and photoresponsive means coupled to each of said outputs such that the photoresponsive means collectively indicate beam spectral properties.  
     
     
         32 . A system according to  claim 30  in which said color filter comprises a set of variable band width, variable base band filters.  
     
     
         33 . A system according to  claim 30  in which said color filter elements exhibit variable dichroic properties in a rotary direction so that selective transmission of one color wavelength and reflection of others is possible.  
     
     
         34 . An image projection system comprising: 
 (1) a light beam source for generating a beam;    (2) a beam modulation system including a carrier for supporting a plurality of gobos;    (3) means for controlling said carrier to position one of said gobos in said beam; and    (4) means for varying the angular orientation, velocity, and direction of a selected gobo, said means for varying engaging said plurality of gobos simultaneously, whereby the generated beam pattern can be modulated by simultaneously adjusting both gobo pattern selection and orientation of the selected gobo.    
     
     
         35 . A system according to  claim 4  in which said liquid cell includes a flexible membrane separating a sealed inner chamber from an outer chamber through which fluid coolant is circulated.  
     
     
         36 . A light projection system for lighting applications having one or more light projectors, said one or more projectors comprising: 
 (1) a light beam source for generating a beam having an intensity suitable for lighting applications;    (2) a folded optical system to reverse the direction of said beam, said optical system including at least one fold back mirror having heat control means for producing a relatively cool light beam.    
     
     
         37 . A light projection system for lighting applications having at least one light projector which includes beam intensity control means, said projector comprising: 
 (1) a light beam source for generating a beam having an intensity suitable for lighting applications;    (2) a controllable dimming means for adjusting the intensity of said beam;    (3) an intensity-indicating feedback device responsive to the adjusted beam and having an output indicative of the intensity level of the adjusted beam; and    (4) a controller responsive to said feedback device and arranged for controlling said dimming means.