The lighting of artwork in museums has traditionally been done by gallery style lighting in which a series of individual lights are mounted on a track and aimed at the artwork with overlapping beam patterns. These lights are located on the ceiling or placed high above the artwork to reduce radiant heat and are normally shielded with a UV reducing filter. These systems work well in commercial spaces but are highly undesirable and impractical in residential settings.
The lighting of art from picture lights is traditionally done with exposed incandescent lamps located in a metal housing that can be rotated to direct the light onto the artwork and prevent direct glare into the viewers eyes. The exposed incandescent lamp generates light by heating the filament to “incandescence”, thereby exposing the artwork to excessive heat. Additionally, these lamps do not properly illuminate the artwork in an even manner.
The prior art also includes fluorescent lamps. Fluorescent sources offer the benefit of producing less heat than incandescent lamps. However, these lamps also produce high levels of damaging UV rays. Furthermore, fluorescent lamps have difficulty evenly lighting an entire artwork due to poor reflector designs and socket shadows occurring between multiple lamps.
Halogen based lamps are another alternative light source. Halogen light sources generate large amounts of heat and some UV rays. Halogen lights are available in various wattages. Some halogen lamps, referred to as MR style lamps, are provided with precise mirrored reflectors. These lamps can produce round, narrow beam distribution that can illuminate the entire height of a piece of art. However, MR lamps generally produce round beams of light down an artwork that are difficult to distribute evenly across the width of the work, particularly when the light sources are mounted close to the artwork.
Recent advances in the prior art include the use of bare halogen lamps in combination with framing shutters or aperture plates. These systems include a single, small light source and limit the projection of light to the area of the canvas. These systems are limited by the fact that the lamp must be mounted at a significant distance out from the artwork in order to evenly illuminate a large piece of art. Examples of these systems are manufactured by DeBruyne Lighting LLC of Florida and Hogarth Fine Art Lighting of England. The system manufactured by DeBruyne includes a UV filter manufactured by Optivex. However, this filter only removes a portion of the harmful UV spectrum. The Hogarth system uses a lamp with a reduced UV ray output rather than a filter. Neither system offers any means of limiting the amount of radiant heat generated by the system. These systems are not generally suitable for lighting larger artworks.
Light generated by most light sources, such as round halogen and incandescent exposed lamps, is not naturally collimated in the direction of propagation of the light on artwork. Collimation of multiple halogen light sources is often desirable to achieve high color rendering or artwork but is normally combined with excessive radiant heat or damaging UV light.
Furthermore, MR style lamps have a circular cross-section. Thus, the generated light beam also has a circular cross-section. Where it is desired to generate a light beam having other than a circular cross-section (e.g., rectangular cross-section) the light beam cannot be efficiently transformed from a circular to non-circular shape.
The present invention is directed to overcoming one or more of the problems set forth above.