LUMINAIRE

RELATED APPLICATION

This application is a utility application claiming priority of United States provisional application with the same title Serial No. 61/691,233 filed on 20 Aug 2012.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention generally relates to an automated luminaire, specifically to an optical system for use within an automated 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 commonly provide control over the pan and tilt functions of the luminaire allowing the operator to control the direction the luminaire is pointing and thus the position of the light beam on the stage or in the studio. Typically this position control is done via control of the luminaire 's position in two orthogonal rotational axes usually referred to as pan and tilt. Many products provide control over other parameters such as the intensity, color, focus, beam size, beam shape and beam pattern. The beam pattern is often provided by a stencil or slide called a gobo which may be a steel, aluminum or etched glass pattern. The products manufactured by Robe Show Lighting such as the ColorSpot 700E are typical of the art.

[0003] The optical systems of such automated luminaires may include a variable diffusion or frost system. Such systems allow the user to soften or diffuse the image for artistic effect. These systems typically comprise pieces of frosted or diffusing optical material which may be moved across the light beam using a motor system. As the diffusing material is moved across the beam it will progressively diffuse or soften the image. Control of the position of the diffusing material allows the user to achieve the desired amount of diffusion or softening. Such a system may be limited in both its range and finesse of control as a single strength of diffusing optical material is used.

[0004] Figure 1 illustrates a multiparameter automated luminaire system 10. These systems commonly 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.

[0005] Figure 2 illustrates a prior art automated luminaire 12. A lamp 21 contains a light source 22 which emits light. The light is reflected and controlled by reflector 20 through optical devices 26 which may include dichroic color filters, effects glass and other optical devices well known in the art and then through an aperture or imaging gate 24. Optical components 27 may include variable diffusion, gobos, rotating gobos, iris and framing shutters. The final output beam may be transmitted through output lens system 31. Lens system 31 may be a glass lens or lens system providing beam angle control or zoom as well as focus adjustment.

[0006] There is a need for an improved variable image diffusion system for an automated luminaire which provides improved range and finer control of the applied diffusion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 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:

[0008] FIGURE 1 illustrates a typical automated lighting system;

[0009] FIGURE 2 illustrates a prior art automated luminaire and;

[0010] FIGURE 3 illustrates the layout of a luminaire embodiment with an improved diffusion system;

[0011] FIGURE 4 illustrates components of a luminaire utilizing an embodiment of the improved diffusion system and;

[0012] FIGURE 5 illustrates a the luminaire embodiment of Figure 4 with the

improved diffusion system repositioned relative to other components in the luminaire;

[0013] FIGURE 6 illustrates components of the improved diffusion system.

DETAILED DESCRIPTION OF THE INVENTION

[0014] 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.

[0015] The present invention generally relates to an automated luminaire, specifically to the configuration of a variable image diffusion system within such a luminaire such that said image diffusion system provides a wide range and fine control of the applied image diffusion.

[0016] Figure 3 illustrates a schematic layout of an embodiment of the invention in luminaire 80 generating a light beam with a beam axis 81. A lamp 71 contains a light source 72 which emits light. The light may be reflected and controlled by reflector 70 through optical devices 76 which may include dichroic color filters, effects glass and other optical devices well known in the art and then through an aperture or imaging gate 74. Optical components 75 may include colored filters, gobos, rotating gobos, iris and framing shutters. The light beam may then pass through variable diffusion system 27 which is capable of being moved backwards and forwards 78 along the optical axis of the luminaire 81 via motor driven mechanism 29. The final output beam may be transmitted through output lens system 31. Lens system 31 may be a glass lens or lens system providing beam angle control or zoom as well as focus adjustment. Output lens system 31 may be capable of being moved backwards and forwards 65 along the optical axis of the luminaire 81 via motor driven mechanism 63. Light source 72 may be a discharge lamp, arc lamp, incandescent lamp, plasma lamp, LED lamp or any other light source as well known in the art. [0017] Figures 4 and 5 illustrate select components of a luminaire embodiment of an improved diffusion system. Light source 52 emits light which is directed along a beam axis 81 through optical devices 56 and 57 which may include dimmers, dichroic color filters, color wheels, effects glass and other optical devices well known in the art. The light beam may then pass through variable diffusion system 27 comprising first optical diffusion flags 30 and 32 and second optical diffusion flags 34 and 36. The resultant output beam may be transmitted through output lens system 61. Lens system 61 may be a glass lens or lens system providing beam angle control or zoom as well as focus adjustment. In this embodiment of the invention, variable diffusion system 27 is able to move back and forth, as shown by arrow 28, along the optical axis of the luminaire. Figure 4 shows variable diffusion system 27 moved back, closer to the source 52 and optical devices 56 and 57, while Figure 5 shows variable diffusion system 27 moved forwards, further away from the light source 52 and optical devices 56 and 57. By thus moving variable diffusion system 27 it is possible to vary the intensity and spread of the diffusion effect created by first optical diffusion flags 30 and 32 and second optical diffusion flags 34 and 36. Output lens system 61 may also be moved 65 along the optical axis 81 of the luminaire, and the combinations of positions of output lens system 61 and variable diffusion system 27 may provide the user with full control of the beam size, focus, and diffusion.

[0018] First optical diffusion flags 30 and 32 and second optical diffusion flags 34 and 36 may be constructed of glass, plastic, quartz, or other transparent, partially transparent, or translucent material as known in the art. The diffusion on the flags may be provided through coating the flags, sand blasting or abrading the flags, engraving the flags, etching the flags, frosting the flags, providing micro-lens structures on the surface of the flags, molding patterns in the flags, embedding diffusing materials within the flags, or any other means for providing diffusion or frosting as well known in the art. First optical diffusion flags 30 and 32 may be of differing construction and diffusing power than second optical diffusion flags 34 and 36.

[0019] Figure 6 illustrates an embodiment of the invention. Variable diffusion system 27 comprises two pairs of optical diffusion flags. First optical diffusion flags 30 and 32 may be opened and closed over aperture 38 through gears 46 and motor 42. As first motor 42 rotates, gears 46 are caused to rotate in contrary directions thus moving attached diffusion flags 30 and 32 in contrary directions. Second optical diffusion fiags 34 and 36 may be opened and closed over aperture 38 through gears 44 and motor 40. As second motor 40 rotates, gears 44 are caused to rotate in contrary directions thus moving attached diffusion flags 34 and 36 in contrary directions.

[0020] First optical diffusion flags 30 and 32 may have the same diffusion density or may differ in their diffusion density from second optical diffusion flags 34 and 36. Light passing through aperture 38 will pass through both first diffusion flags 30 and 32 and second diffusion flags 34 and 36 and the resultant image will be affected by the combination of the first and second diffusion flags.

[0021] Motor control system (not shown) may control first motor 42 and second motor 40 independently. In one embodiment the control of first motor 42 and second motor 40 is synchronized such that a single control input from the user may control both motors. As the user requests increasing diffusion the motor control system will operate first motor 42 thus closing first diffusion flags 30 and 32. Once first diffusion flags 30 and 32 are partially or substantially closed then the motor control system may operate second motor 40 thus additionally closing second diffusion flags 34 and 36. The resultant projected image will be diffused by the combination of both first and second diffusion flags. By using the combination of first and second diffusion flags the disclosed system provides improved range and resolution of applied diffusion.

[0022] In a further embodiment first diffusion flags may have a first diffusion density and second diffusion flags may have a second diffusion density that is greater than the first diffusion density. When both first diffusion flags and second diffusion flags are moved across the light beam then a combined diffusion density is provided that is greater than both the first and second diffusion densities.

[0023] In a yet further embodiment the motor control system may move first and second diffusion flags concurrently.

[0024] Motors 40 and 42 may be small low powered motors of type selected from but not limited to stepper motors, servo motors, linear actuators or low powered DC motors.

[0025] The illustrated exemplary embodiment utilizes two sets of diffusion flags, however the invention is not so limited and in further embodiments any number, two or greater, of sets of diffusion flags may be used.

[0026] In Figure 3, the diffusion flag assembly 27 is mounted on a carrier 28 which employs a linear drive 29 to move the diffusion assembly 27 along direction 78 along the optical axis 81. Similarly the output lens assembly 31 is mounted on/in a separate carrier 62 which employs a linear drive 63 to move the lens assembly 31 along direction 65 along the optical axis 81.

[0027] In some embodiments the movement of carrier 28 and carrier 62 are automatically coordinated such that a change of diffusion can be synchronized with a change in focus or zoom of the luminaire. In further embodiments the movement of diffusion carrier 28 is automatically coordinated with the operation/movement of the diffusion flag pairs 34 and/or 36. Such coordination allows for an improved range of diffusion strength. As the diffusion flag pairs close, the carrier 28 may be moved so as to also affect the diffusion strength. In other embodiments the movement of output lens carrier 62 is automatically coordinated with the operation/movement of the diffusion flag pairs 34 and/or 36. In further embodiments the user is allowed to override the automated coordination of movements of the carriers 28, 62 and/or flag pairs 34 and 36.

[0028] 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.