This invention relates to illumination of artwork.
Artwork can be mounted in holders including picture frames. The artwork may be covered with a clear sheet of glass or plastic. Photographs, pictures or other artwork having a substantially flat surface are well suited for having a clear cover. The clear cover can help protect the artwork from damage yet permit viewing of the underlying work. External lighting may be used to illuminate the artwork for viewing when it is desired to enhance the ambient light. The artwork may be viewed using reflected or direct light.
Transparent materials may be placed in front of artwork so that the artwork may be viewed through material. For example, glass or plastic may be used to protect the underlying artwork. External lighting on the artwork may result in glare off of the front surface of the transparent material. Use of a matted glass or plastic may reduce glare, but can cause distortion of the photograph or artwork being displayed
Photographs may be created using a trichromatic system using, for example, the colors red, green and blue. Computer printed artwork may be created using a tetrachromatic system using, for example, the colors cyan, magenta, yellow and black. General printed artwork may feature even more color components for extremely high color rendering. These systems may be designed for use with reflected light. That is, external light that is reflected off of the front surface of the artwork.
Like elements have the same number in the various figures.
The systems and techniques disclosed utilize reflected light to illuminate artwork.
Some or all of the implementations of the disclosure have one or more of the following advantages. A reduction in glare by the use of reflected light to illuminate artwork. Using reflected light to add the dimensionality without introducing undesirable color shifts that may result from use of transmitted light. Some implementations provide for even distribution of light across the front surface of the artwork.
These benefits may be realized by utilizing evanescent waves to scatter light from the front surface of a photograph, print or other artwork. Evanescent waves are light waves trapped at the surface of a smooth, transparent body. Placing a printed photograph in intimate contact with a transparent surface allows the photograph to interact with evanescent waves in a manner that results in light being forwardly scattered. The interaction of the photograph with the evanescent waves can allow for enhanced lighting on materials of arbitrary thickness or composition. The lighting system disclosed also can preserve the color rendering properties of the artwork being displayed and provide enhanced dimensionality associated with backlighted artwork.
The disclosed lighting system can be provided by a light source placed against one or more of the sides of a front panel that covers the artwork. The front panel can be made of transparent materials including glass, acrylic and plastic, so that the underlying artwork may be viewed through the front, or viewing, surface of the front panel. In an implementation, the light source is placed along one or more sides that are perpendicular to both the viewing surface and the artwork being displayed.
The artwork or photograph and the back surface of the front panel can be in intimate contact for the side lighting to be scattered evenly off of the artwork and to the observer. A back panel may be used to press the photograph against the back surface of the front panel. Unevenness of contact between the photograph and the front panel may lead to dim lighting or non-uniformity of lighting across the surface of the photograph. Factors that may result in these undesired lighting include deviations in the planarity of the front panel and the back panel used to press the photograph against the front panel and surface textures of the photograph.
The compliant layer 420 can allow intimate optical contact between the artwork 130 and the front panel 410. When intimate contact is established, light that propagates inside the front panel 410 may interact with the artwork 130 in such a manner that light is scattered in the forward direction towards the observer.
In an implementation, the compliant layer 420 is separate and distinct from the front panel 410 and may thus be removed or replaced. In other implementations, the compliant layer 420 is adhered to the front panel 410.
Applying pressure to the backside of a photograph forces it into intimate contact with the compliant layer, resulting in substantially all of the artwork being in intimate optical contact with the front panel. This in turn allows the front surface of the artwork to interact with light injected into the side of the front panel in a manner that scatters it in a forward direction.
The compliant film can be transparent and yield slightly under pressure. A compliant film may be a separate piece or coated onto one side of the front panel. For example, a transparent silicone film may be applied to a sheet of acrylic, glass or polycarbonate to create the compliant layer. Other soft silicones, latex, urethane, vinyl or epoxy materials that are transparent and non-rigid also can provide suitable compliant films. In some circumstances semi-liquid materials such petroleum or silicone jellies or oils also may provide a compliant film.
The back plate should be sufficiently rigid to provide substantially uniform pressure to force the artwork into the compliant film. In an implementation, the front panel is planar and the back panel will be slightly convex to better distribute force to the center of the artwork being displayed. This arrangement may help retain the center of the artwork in intimate contact with the compliant layer as pressure is applied to the back panel. In another implementation, the front panel is convex and the back plate is planar. In yet another implementation, both the front panel and the back panel are convex.
The front panel is preferably transparent and rigid. Suitable materials for the front panel includes glass, cast acrylic, extruded acrylic, polycarbonate and epoxy.
he light source may be any compact white light source including fluorescent lights, cold cathode fluorescent lights, incandescent lights, white LEDs, EL strips and combinations of two or more single color LEDs that can be adjusted to yield a metameric white light. The light source can have an optical housing to increase the efficiency of light injection into the front panel. Compact fluorescent tubes, EL strips and white LEDs may be particularly well suited as light sources. The light source may include a linear strip of red, green and blue LEDs that create a metameric white light. This light source may provide color rendering as the wavelengths of light emitted by the LEDs can be chosen to match the reflectance spectra of the dyes or inks used in the prints or artwork being displayed. Such a light source could be used to further enhance the dimensionality of artwork being displayed by providing superior color rendering and increasing the saturation of displayed colors. These LED light sources need not be limited to three colors. Additional wavelengths may be incorporated to further enhance the color rendering and saturation.
As mentioned above, lighting efficiency can be increased by incorporating a reflector around the light source to direct substantially all the light into the front panel in such a manner that it is confined in the panel by internal reflection. Light sources may be positioned along one or more sides of the front panel. Lighting efficiency may also be improved by incorporating reflective coatings or layers on the sides of the front panel without light sources.
In some implementations, using a combination of LEDs to produce metameric white light, it may be desirable to allow adjustments to be made to the relative intensities of the different LEDs. This will allow changes to be made in the color temperature of the light source and in turn allows users of the lighting system to select a “mood” for lighting.
A light source that includes ultraviolet lamps or ultraviolet LEDs may be used for artwork that has phosphorescent and/or fluorescent materials. Addition of ultraviolet light could increase the phosphorescent or fluorescent response of the image and enhance light output.
Other implementations are within the scope of the following claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US05/21600 | 6/17/2005 | WO | 00 | 9/27/2007 |
| Number | Date | Country | |
|---|---|---|---|
| 60581230 | Jun 2004 | US |