Wall hangable window simulating unit
This is a continuation of application Ser. No. 07/963,518 filed Oct. 20, 1992, now abandoned, which is a continuation of Ser. No. 07/787,779, filed Nov. 6, 1991, now abandoned, which is a continuation of Ser. No. 07/363,740, filed Jun. 9, 1989 now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to units for simulating natural daylight and specifically to simulated window units for mounting on the wall (windows and doors with windows) and the ceiling (skylights) of a structure. 
     BACKGROUND ART 
     It has become quite common in large buildings nowadays to design many interior spaces, including working areas and public rooms, without means for supplying natural daylight. This creates various problems associated with such windowless working environments. The inventor has observed that environments which are windowless and deprived of any significant source of natural daylight, are known to lead to physical and psychological problems which, in turn, decrease the productivity of people working in the windowless offices. 
     The inventor has conducted extensive studies to determine the influences of light, color and lack of windows on the mood, health and productivity of employees. He has observed that the quality of light, presence of windows, and even the views through a window can greatly effect the mood, work, and mental and physical health of people. 
     The inventor has observed that most people dislike windowless environments. They feel boxed-in, disconnected, and cheerless. The problem is compounded during fall and winter by dwindling hours of sunlight. Energy and productivity often sag. 
     Windows and sunlight can affect a person&#39;s rhythms and moods profoundly. Light influences how one interacts with other people, one&#39;s happiness, productivity and even health. People gravitate towards windows because they instinctively understand that windows and sunlight make them feel better. 
     It has been known in the art to provide various illuminated, decorative panels, room display units and units with the appearance of windows mainly to enhance the aesthetic appearance of interiors or for advertising purposes. Examples of such panels are, for example, suggested in British Patent No. 2,084,461, or U.S. Pat. No. 4,034,494. The structure of both display units have significant thickness of the panel boxes, do not emanate light evenly, do not emanate an &#34;outdoors&#34;  spectrum of light, and thus do not create an impression and feeling of natural windows. 
     Light-boxes which are used for backlighting of advertising transparencies and decorative panels have to be 5&#34;-8&#34; deep in order to provide evenly diffused light. If they were used as part of simulated windows, such prior art light boxes would cause the appearance of the unit to be bulky and disturbingly unnatural on the wall or on the ceiling, thus negating the attempt to make the unit look like and have the psychological impact of a realistic-looking window. 
     Various attempts have also been made in the lighting industry to improve the working environment of interiors supplied with artificial light by directing the improvements to the quality of the artificial light. It is known, for example, to provide lighting fixtures with polarizing panels to reduce glare which, in turn, tends to reduce fatigue and headaches among people. In addition, there are available lamps (bulbs) which emit light similar to the daylight spectrum. Some lamps have characteristic colors which have been shown to be helpful in terms of color accuracy and color preferences to the human eye. 
     In recent years &#34;light therapy&#34; boxes have also been available. Light therapy is now frequently prescribed by physicians for a number of problems, most commonly SAD (Seasonal Affective Disorder), a depression thought to be caused by insufficient exposure to daylight. These light boxes emit intense light with a daylight spectrum, but are unattractive and generally uncomfortable to use. They are typically prescribed for periods of 30 minutes to 3 hours a day. Their shape, light unevenness and intensity and significant cost make them unsuitable for use as part of a daylight window simulation unit. 
     SUMMARY OF THE INVENTION 
     The inventor has discovered that simulated windows with simulated natural daylight effects, in such windowless environments, are very beneficial. 
     The present invention focuses on the creation of lighting units which through their structural appearance and quality of delivered light create an illusion of supplying natural daylight through a window. 
     The simulated daylight window of the present invention features scenic &#34;views&#34; built into a custom window frame and backlit by special uniform light similar to natural sunlight, with light treatment which cuts glare and improves visual effectiveness. 
     The natural daylight window simulating units of the present invention can be incorporated in the form of simulated window units for mounting on the wall, door units with window panels, or skylight units for mounting, for example, in the suspended ceiling of interiors of a structure. 
     One purpose of the present invention is to provide lighting units which create both the impression and the physical effects to a person, of receiving from such units, natural daylight, especially in a windowless environment. 
     It is another purpose of the present invention to provide units having the appearance of a genuine window with a sunny view or a real skylight, and the psychological benefits which this provides. 
     The applicant has combined various factors including a high quality backlighting system, a structural real window appearance of the unit, for example, through a shallow dimension of the unit, and a particular pictorial presentation simulating the outside environment and featuring sunny scenic views evenly backlighted, which together result in the creation of simulated natural daylight windows. 
     These natural daylight window simulation units were developed to help counteract mood, vision, and productivity problems often linked to windowless environments and seasonal changes in natural light. The present invention simulated window units are to give people the positive, uplifting feelings they would normally get from a real window and a pleasant sunny view. 
     In one preferred embodiment, a simulated natural daylight window unit includes a supporting structure, a sheet of transparency with printed indicia representing a view, and a natural-like daylight backlighting system for providing backlighting for the imprinted transparency. 
     The natural-like daylight backlighting system includes a source of light which provides light having a spectrum similar to that of the daylight spectrum, as well as high color accuracy and color preference. The system also includes means for providing evenly diffused backlighting for the imprinted transparency in a thin lighting system. Also, means for reducing glare on surfaces in the room may be provided to further enhance the quality of the light and accuracy of colors. 
     The primary features which were combined to make such simulated window and daylight units effective in providing the &#34;feeling&#34; of a genuine window in the room, include a scenic view back-illuminated by a natural-like daylight backlighting system combined with a very thin backlighting structure which is necessary, for example, in order for the window unit to appear natural when secured or hung on a wall. 
     The appearance of the window unit is an important factor and provision of, for example, venetian blinds, provision of the pictorial presentation with sunny views and appropriate scale and perspective, greatly enhance the natural window-like effect. Also, mounting of the unit at the window level is crucial. 
     It is also desirable to control the brightness of the backlighting for a particular room setting, the transparency used for pictorial representation, and for individual taste. The window unit should preferably include a dimmer system for the necessary adjustment of the brightness. Also, appropriate window molding to give a three-dimensional impression to the view, results in the increased effect of the natural-looking window. 
     The simulated daylight window unit, with appropriate molding, can also be mounted on the ceiling as a simulated skylight unit. However, in another embodiment, the skylight unit can be simply fitted into a conventional, fluorescent fixture frame, mounted in a suspended ceiling and use the fluorescent light fixtures, retrofitted with lamps with light spectrum similar to that of the day spectrum, and modified to spread the light out more evenly, as a source of illumination. Provision of a transparency with an imprinted sky view and a vertically-polarizing panel, which are backlighted, by such source of lighting, result in a unit with a natural skylight effect. The vertically-polarizing panels increase color accuracy and contrast of the backlighted view and the vertical-polarizing panel along with the transparency fitted in an overhead fluorescent fixture, produces a naturally-appearing view of the sky. The polarizing panel reduces direct glare as well as reflected glare from room surfaces (veiling glare). 
     The present invention will now be described in more detail with reference being made to the accompanying drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of one embodiment of a simulated day-light unit according to the present invention in the form of a window-unit mounted on a wall; 
     FIG. 2 is a view of another embodiment of a simulated daylight unit in the form of a skylight unit mounted in a suspended ceiling; 
     FIG. 3 is a front elevational view of the window unit with partial cross-section showing front layers; 
     FIG. 4 is a view of the window-unit of the present invention taken from the rear side showing location of the lighting fixtures; 
     FIG. 4a is a view similar to that of FIG. 4 of another embodiment of the window unit; 
     FIG. 5 is a cross-section taken along lines V--V&#39; of FIG. 3; 
     FIG. 6 is a cross-section taken along lines VI--V&#34; of FIG. 3; 
     FIG. 6a shows another embodiment of FIG. 6; and 
     FIGS. 7a and 7b show, respectively, an end view, partially in cross-section of a skylight unit and a detail showing a cross-section view of the front layers. 
    
    
     BEST AND VARIOUS MODES OF CARRYING OUT THE INVENTION 
     Referring now to the drawings, FIG. 1 shows one preferred embodiment of the present invention simulated natural-like daylight unit in the form of a simulated window unit designated as 100. 
     The window unit 100 includes a very shallow, box-like, supporting structure 20. The box-like structure 20 includes a substantially rectangular bottom member 21 which is to be placed on a wall in a windowless room, and four outwardly extending, narrow side members 23, each having one edge connected to one of the sides of the bottom member 21. The front of the supporting box-like structure defines an opening in which a multi-layer front member 31 of the simulated window unit 100 is supported. 
     The front member 31 of the simulated window-like unit, as best shown in FIGS. 5 and 6, includes at least a sheet of transparency 32 which has an indicia imprinted thereon representing an outdoor view and a transparent sheet, for example made of acrylic material 30 positioned in front of the sheet 32. This sheet 30 is provided primarily as protection and support for the remaining layers of the front member 31. 
     In order for such simulated daylight window unit to appear as a real-looking, natural window when hung on the wall, the entire structure of the simulated window unit has to very shallow. The depth of the present invention box-like structure 20 is about 2 to about 3 inches which is significantly less than in conventional backlighted panels having a depth of about 51/2&#34;-8&#34;. Typical simulated daylight window units are 34&#34; high and 44&#34; wide. 
     On the other hand, in order to create a feeling of a natural daylight being delivered into the room from such simulated window unit, it is important that the light is evenly diffused through a transparency with an imprinted view representation. The backlighting system, used for illuminating the imprinted sheet of transparency has to simulate a day-like light source to create an impression of a natural, outdoor light being delivered into the room, and at the same time provide a backlighting system of very small thickness to fit into the shallow dimensions of the box-like structure. 
     In the preferred embodiment, the backlighting system of the present invention uses, as a source of light, fluorescent fixtures. 
     As shown in FIG. 3, 4, 5 and 6, the box-like supporting structure 20 of the window unit 100 houses therein at least one fluorescent fixture 24 which is mounted on the bottom member 21 between mounting members 22 which in turn are supported in the box 20. 
     To provide the above quality of the backlighting, the present invention simulated units employ fluorescent fixtures having a light spectrum which is similar to the outdoor daylight spectrum. The backlighting system is also designed to maximize color correctness and color preference and to minimize glare. It is also important for the entire backlighting system to generate minimum heat output, such as to minimize its effect over time on the imprinted dyes, and have flicker-free performance, and very low sound levels. 
     Some of this is accomplished by the use of high frequency electronic ballasts which give off less heat, substantially eliminate flicker, particularly 60cps flicker and are also much more quiet in operation than standard ballasts. 
     The fluorescent lamps and ballasts having the above qualities are readily available on the market. The lamps are chosen such as to have most of the natural spectrum plus some additional phosphors which enhance different colors to the way that is most preferred by people and provides high &#34;color accuracy&#34;. 
     In the preferred embodiment, the front member 31 of the window box-like structure 20, in addition to the sheet member of transparent material 32, with the sheet of a polyacrylate 38 at one side, a thin, clear polyester sheet 30 can be provided on the other side of the sheet member 32 for additional support of the entire front member&#39;s structure. Also, a vertically-polarizing panel member 34 can be advantageously used. The function of the vertically-polarizing panel member 34 is primarily to reduce glare, and therefore improve the quality of the light being delivered by the simulated daylight window unit. The vertical polarization also contributes to higher accuracy of the colors. 
     A most crucial condition for the present invention natural daylight window simulation units is to ensure, in spite of the shallow structure of the unit, even diffusion of the natural spectrum light directed from the fluorescent lamps over the entire sheet of transparent material with an imprinted view representation. In the preferred embodiment of the present invention, such provision of an evenly diffused backlighting in a very thin backlighting structure is accomplished by the use of the principles of total internal reflection, using a 3M Brand Scotchlamp Film™ (SOLF) 
     Such design includes a 3M SOLF film member 36 for reflection or transmission of the light provided by the fluorescent fixtures. However, other materials providing total internal reflection can be used to reflect or transmit the light. As a part of this lighting panel system, the bottom surface of the supporting box-like member 20 is designed as a very highly specular reflecting surface near fluorescent lamps falling off to more diffuse reflective surface as the distance from the lamps increases. The remaining interior surface of the box-like structure including side member 23 should have a highly specular reflective finish. 
     This geometry of differing reflectivity surfaces of the interior sides and back of the light box, combined with the characteristics of the 3M SOLF film on the front surface, has the effect of controlling the &#34;escape&#34; of the light through the front surface (when the incident angle exceeds the angle of total internal reflection) such that a substantially even brightness results along the entire front surface of the simulated window unit. The very thin light box can be considered a light pipe with a geometrically-controlled release of the light. 
     The appearance of the simulated window unit as close as possible to a real window, is an important factor, and in addition to its &#34;thinness&#34; provision of, for example, venetian blinds 40, provision of the pictorial presentation 31 with sunny views and with an appropriate scale and perspective, greatly enhance and ensure the natural window-like effect. Also, hanging of the simulated window unit in the windowless room at a real window level as opposed to a picture level is crucial. 
     It is also desirable to control the brightness of the backlighting for a particular room setting, the transparency used for pictorial representation, and for individual taste. The window unit can, if desired, include a dimmer system for adjusting the brightness. Also, appropriate molding 41 together with protruding window sill 26 on the front part of the box-like structure 20 gives a three-dimensional impression to the view 31, and results in the increased effect of the natural-looking window. 
     Other factors adding to the quality of simulation which causes the desired impact on people, are the windowsill, the even and natural daylight spectrum light of appropriate intensity, the lack of flicker and sound, etc. Other features which might be added include a fan for a &#34;breeze&#34;, external sounds and smells, 3-dimensional effects, etc. The simulated window units, according to the present invention in other embodiments, may include automatic changing of views, movement, electro-optic/HDTV types of images, piping in of real outdoor views or images via fibre optics, varying the brightness or position of the sun in time to simulate dawn to dusk, etc. 
     FIGS. 4a and 6a show another embodiment of the simulated window unit 100 which is useful for providing high intensities of light when desirable and yet still retaining the qualities of thinness and evenness of light necessary for the effect. In this embodiment, the SOLF sheet layer 36 is eliminated, while additional lamps are added, and the evenness is accomplished by placing a strip of diffusing material 50 such as 3M Scotchtint over the &#34;hot&#34; spots of the fluorescent lamps 23 facing the front of the window unit, and spacing the fluorescent lamps such that the overlapping intensities due to each add up to the required levels of evenness. The entire interior surface of the light box is highly reflective in this embodiment. 
     The simulated daylight window unit described above can also be mounted on the ceiling as a simulated skylight unit. FIGS. 2 and 7a, 7b show another embodiment of the present invention daylight unit in which the skylight unit 200 is simply fitted into a conventional, fluorescent fixture frame, mounted in a suspended ceiling 10 and uses the fluorescent light fixtures 23 with strips of diffusing material 50, with a light spectrum similar to that of the day spectrum, as a source of illumination. 
     As best shown in FIGS. 7a and 7b, a multilayer front member 31 of the skylight unit 200 includes a vertically-polarizing panel 34, a sheet member 32 made of transparent material with imprinted indicia representing a sky view and acrylic lens member 30. The imprinted view representation could also be provided directly on the vertically-polarizing panel 34 or on the acrylic lens 30. The combination of the lighting source delivering light having a spectrum similar to the daylight spectrum, diffused over a multilayer member with imprinted representation of the sky view, results in the ceiling unit with a real sky-light effect. 
     Although the principles of the present invention have been described with reference to a particular embodiment, by way of example, it is understood that modifications may suggest themselves to those skilled in the art and it is intended that such modifications fall within the scope of the claims.