Optical: systems and elements – Single channel simultaneously to or from plural channels
Reexamination Certificate
1999-03-26
2001-08-28
Epps, Georgia (Department: 2873)
Optical: systems and elements
Single channel simultaneously to or from plural channels
C359S622000, C359S623000, C359S626000, C362S297000
Reexamination Certificate
active
06282027
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to lighting instruments, and especially to devices and apparatus for controlling the distribution of light energy in non-imaging illumination applications.
DESCRIPTION OF RELATED ART
Four qualities of lighting as described by Stanley McCandless in his book “A Method of Lighting the Stage” are intensity, color, distribution, and movement. Whereas intensity and color may be said to refer to attributes of particular light beams, distribution refers to the arrangement of light sources about the stage and the directions in which they are aimed. Intensity, color, and distribution are primary qualities, whereas movement is emergent from changes in the primary qualities. Movement in this sense occurs as the condition of the other three qualities changes over time. A simple adjustment of intensity results in movement. No change in any of the other three qualities can occur without resulting in movement, and movement cannot occur without the passage of time from moment to moment.
The passage of time, over the years, has seen all three of the primary qualities of lighting become subject to motorized mechanization and computerized remote control so that in the case of distribution, movement (in a conventional sense) has become overtly mechanized. Moving lights, virtually unheard of twenty years ago, have revolutionized the art of lighting the stage, enabling dynamic lighting effects not possible before the advent of computer-controlled lighting systems having automatically variable qualities. After the novelty of overtly dynamic movement subsides, an appreciation of subtlety once again becomes possible so that we might consider the quality of distribution from the aspect of variable beam divergence or beam spread.
In stage lighting, it is often desirable to expand the light beam from a so-called wash luminaire to illuminate a broader area. A wash luminaire can produce such an effect using a light source and a concave reflector which are moveable with respect to a lens, such as disclosed in U.S. Pat. No. 3,428,800 or in U.S. Pat. No. 3,665,179. The divergence angle of the light beam varies depending upon the position of the source and reflector with respect to the lens. Popular variable-divergence luminaires, such as the Cadenza PC manufactured by Rank Strand of the United Kingdom and the 2KW Fresnel manufactured by Mole-Richardson of California and others, use such an optical system to control the divergence angle of the light beam projected by the luminaire. A positive, or convex, front lens illuminated by a lamp and retroreflector combination produces a substantially columnar light beam and projects a relatively small pool of light when the lamp is placed at the focus of the lens. As the lamp and reflector combination is moved in either direction away from the focus of the lens, the beam diverges from columnar to project a larger pool of light. Such a system is quite large and requires many inches of travel for the lamp and reflector combination along the optical axis of the lens. The carrier mechanism of these luminaires is typically manually adjustable and the large glass front lens, typically eight to ten inches in diameter, is thick and heavy even with the significant weight reduction gained by the Fresnel design used by Mole-Richardson.
Another common system for controlling the divergence angle of a light beam is disclosed in U.S. Pat. No. 4,602,321 and uses a lamp which is movable with respect to a parabolic reflector. When the lamp is placed at the focus of the reflector, a substantially columnar light beam emerges and projects a small pool of light. As the lamp is moved rearwardly along the optical axis of the reflector and away from the focus of the reflector, the beam diverges from columnar to form a larger pool of light. This system requires an adjustable carriage for the lamp socket and frequently requires provisions for minor (manual) adjustments along two additional axes orthogonal to the optical axis, so as to maintain proper alignment of the lamp on the optical axis, in addition to motorized adjustment along the optical axis for controlling beam divergence.
Many commonly used systems for controlling the divergence angle of a light beam use two or more lens elements is series and in combination with a fixedly mounted lamp and a fixedly mounted reflector. In these systems, one or more of the lens elements are movable with respect to the lamp and reflector to vary the divergence angle of a light beam formed thereby. Some common examples are disclosed in U.S. Pat. Nos. 2,076,240; 2,650,292; 2,950,382; 3,302,016; 3,594,556; 4,462,067; 4,519,020; 4,709,311; 4,739,456; 5,029,992; 5,404,283; among others. Some of these systems are used in image-projecting applications in which a hard-edged spot of light is projected onto a distant surface such as a stage floor or backdrop, and may also be used to project complex images formed by objects placed in a focal plane of the projection lens system, such as described, for example, in U.S. Pat. No. 4,779,176.
Another, unique system for controlling the energy distribution of a light beam in a non-imaging application is disclosed in U.S. Pat. No. 5,774,273 and uses a variable-geometry liquid-filled lens having a deformable, transparent membrane supported by a transparent, multi-cellular structure forming an array of variable-power lenslets. An optically clear liquid is pumped into or out of the structure to deform the membrane into an array of convex or concave lenslets having adjustable optical power to control energy distribution. A motorized pump is used as the actuator, and the system may be operated by remote control. It is nevertheless desirable to have a solid-state apparatus, not relying upon liquid components, for controlling the energy distribution of a light beam in non-imaging applications, which apparatus can economically be made large in diameter and yet be light-weight and operable over a short distance along the optical axis of a luminaire.
SUMMARY OF THE INVENTION
The present invention provides a solid-state apparatus which is economically made, is scalable to large diameters yet operates over a short distance along the optical axis of a luminaire to control the distribution of light energy in non-imaging illumination applications.
In accordance with the present invention, an apparatus for controlling divergence of a beam of light comprises a first multiple-lens array including a plurality of plano-convex lenses arranged in a pattern and supported on a transparent substrate; a second multiple-lens array including a plurality of plano-concave lenses arranged in a pattern and supported on a transparent substrate, the first and second multiple-lens arrays being formed so that a curvature of convex lens surfaces of the first array matches a curvature of concave surfaces of the second array, and each convex lens surface of the first array corresponds to and is aligned with a matching concave lens surface of the second array; the first and second multiple-lens arrays being disposed serially and coaxially in a light beam path such that convex lens surfaces of the first array are generally adjacent and coaxially aligned with concave surfaces of the second array; and one of the multiple-lens arrays being movable coaxially with respect to the other multiple-lens array.
REFERENCES:
patent: 2076240 (1937-04-01), Levy
patent: 2650292 (1953-08-01), Strong
patent: 2950382 (1960-08-01), Hatch
patent: 3302016 (1967-01-01), Larraburu
patent: 3428800 (1969-02-01), Levin et al.
patent: 3594566 (1971-07-01), Knelsley
patent: 3665179 (1972-05-01), McLintic
patent: 4462067 (1984-07-01), Altman
patent: 4519020 (1985-05-01), Little
patent: 4602321 (1986-07-01), Bornhorst
patent: 4630902 (1986-12-01), Mochizuki et al.
patent: 4632522 (1986-12-01), Ishitani
patent: 4709311 (1987-11-01), Bornhorst
patent: 4739456 (1988-04-01), Little
patent: 4779176 (1988-10-01), Bornhorst
patent: 4867514 (1989-09-01), Waldron
patent: 5029992 (1991-07-01), Richardson
patent: 5237367 (1993-08-01), Kudo
patent: 540
Carr & Storm, L.L.P.
Epps Georgia
Thompson Timothy J
Vari-Lite Inc.
LandOfFree
Zoomable beamspreader with matched optical surfaces for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Zoomable beamspreader with matched optical surfaces for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Zoomable beamspreader with matched optical surfaces for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2537271