Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
Light diffusing systems suspended from a ceiling have been used to
distribute illumination from ceiling mounted fluorescent or similar lamps.
Often these systems have employed translucent planar panels to form a contin-
uous, flat diffusing surface extending over large portions of a ceiling.
These monotonous expanses of illuminated panel have often contributed to an
oppressive, non-productive room environment which is further exacerbated by
the glare produced by such a system. The lamp fixtures and suspending
structure have often cast shadows on the diffusing panels, which serve not
to alleviate the monotony of the diffuser surface but to cause non-uniform
illumination of the room, and confusing multiple shadows on work areas.
Attempts to overcome these problems by introducing new systems which recess
the diffusing panels or employ secondary diffusers have resulted in a pro-
liferation of parts to be assembled during installation of each new system.
The corresponding increase in man-hours required for complete assembly has
resulted in higher costs without overcoming all of the defects of the prior
art.
Summary of the Invention
The present invention is directed toward a light diffusing system
which overcomes the problems of the prior art and provides a textured ceiling
which is a source of non-glaring illumination and is pleasing to the eye. It
comprises a multiplicity of rectangular or square panels, each formed in a
coffer configuration defined by a lateral translucent portion supported by
upwardly extending walls which terminate at their lower extremities in hori-
zontally extending flanges. A framework of T-bar members defining square
openings which is suspended from the ceiling supports the panels with the
flanges resting on the T-bars and the coffer cavities opening downward. The
upwardly extending walls are tapered in thickness from the flange to the
lateral portion, and are painted on their ceiling-facing side with an opaque
color coating. Light from ceiling-mounted lamp fixtures diffuses through the
lateral translucent portion of each panel, providing illumination to the area
below and also illuminating the walls of the coffer. The taper of the walls
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causes them to reflect more lights from the upper portions than from the lower,
so that the color reflected from the walls of each panel has an intensity
gradient which enhances the depth effect of the coffer. The coffer configura-
tion removes most of the lateral diffusing surfaces from direct view, greatly
relieving the glare and brightness of the ceiling. Furthermore, the enhanced
depth effect of the coffer panels and the color of the walls of the coffers
provides a pleasant visual interest which is lacking in prior light-diffuser
systems. Because each panel is a molded single unit, installation is simple
and economical, and maintenance of the lamp fixtures is easily facilitatedO ~ -
The panels may be used in luminous bays interspersed with acoustical tile
or other suspended ceiling material, or they may be employed as a complete
suspended ceiling.
The Drawing
Figure 1 is a perspective view of the present invention as seen
from above.
Figure 2 is a perspective view of the present invention as seen
from below.
Figure 3 is a sectioned side view of the present invention.
Figure 4 is an exploded sectioned side view of a portion of a
light diffusing panel.
Figure 5 is a view similar to Figure 4 illustrating a modified
form of the invention.
Description of the Preferred Embodiment
The light diffuser system of the present invention is illuminated -;
from above by lighting fixtures 5 secured to a ceiling, as shown in Figure 1.
Suspended from the ceiling by the hanger rods or wires 6 is a framework 7 of
T-bar members. Each T-bar member includes a vertical portion 8 and horizont- ~`
ally extending portions 9, with the members defining square openings. Into
each of the openings a square light diffusing panel 11 is placed, resting on
the horizontal portions 9 of the framework on all sides, and diffusing the
light from fixture 5 to the area below. It should be noted that the framework
may be formed with openings of various standard sizes with the panels dimen~
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sioned to match, thus providing a selection of panel sizes to suit a wide
variety of situations.
Each light diffusing panel is formed by molding translucent white
acrylic plastic, plexiglass or the like into a single unit with a square
coffer configuration, as shown in cross-section in Figure 3. The panel 11
includes a horizontal flange 12 formed about the perimeter of the panel and
resting on the horizontal portion 9 of the framework on all sides of the panel.
Upwardly directed walls 13, which are inclined inwardly from vertical toward
the center of the panel, support a laterally extending planar portion or top
wall 14, and define a coffer cavity 20 therebetween which opens downward.
Walls 13 are joined to the flanges 12 by a shoulder 15. All of the vertices
are rounded to prevent stress concentrations.
Because each light diffusing panel is of unitary construction, it
may be appreciated that installation is quick and economical. Each panel is
lifted through its opening diagonally, turned and properly oriented, and set
in place. No screws or bolts or other fasteners are required.
As shown in Figure 4, each of the walls 13 is tapered in thickness
from the base 16 to the top 17. The ceiling facing surface of the walls is
painted or otherwise coated with an opaque pigmented coating 19. The coat-
ing blocks all light from the lamps above, so that the only illumination of
the walls 13 comes from the light diffusing through the white, translucent ;-
portion 14. Because each wall is tapered in thickness, the incident light
from 14 is reflected more strongly by the pigmented coating 19 at the top 17
of the wall, and is more dispers0d and less intense at the thicker bottom 16
of the wall. Thus the color reflected from the wall has a gradient of decreas-
ing intensity from the top to the bottom of the wall. This gradient serves
to enhance the perceived depth of the cavity 20 and making the panels 11
more visually interesting and aesthetically pleasing.
The panels of the present invention may be arrayed in luminous
bays interspersed with acoustical ceiling tile or the like, or may be extended
over an entire ceiling, as shown in Figure 2. It may be appreciated that due
to the coffer configuration of the panels 11, the lateral, light-diffusing
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portions 14 are only partially visible at most from below, thus reducing
glare and brightness while delivering optimum illumination. The luminous
portions 14 set off in the coffer cavity by the colored walls 13 and the dark
frame of the framework 7 provide a striking and effective, yet economical
light diffusing system.
It should be noted that the taper of the walls 13 may be invert- -
ed; i~e., thicker at the top portion 17 and thinner at the lower extremity 16,
thereby inverting the intensity gradient and creating another striking yet
pleasing visual effect. Also, it will be appreciated that instead of painting
or otherwise laminating an opaque coating or layer on the outer surfaces of
walls 13, the same general effect could be obtained by placing an opaque
collar or sleeve over the walls.
A modified form of invention is disclosed in Figure 5 in which
the walls 13 are not provided with their outer opaque layer or coating, In-
stead, an acoustical ceiling is readily provided by coating or spraying a
conventional acoustical material on the inner surface of walls 13 to form a
layer 21. Such layer may be formed of any suitable open cell sound absorbing
material, such as polyurethane foam, sprayed flocking and the like.
With this latter arrangement, light will only pass through the
horizontal translucent wall portion 14, with the remainder of the coffer
bearing the sound absorbing material.
As a further feature of the invention, it has been found that the
color provided in the coating 19, described in the first described embodiment,
has a substantial effect in providing novel harmonized lighting in a room.
In other words, by selecting various colors for the coating, the color tem-
perature of the room can be readily modified. For example, by providing a
coating possessing an amber color, blue light will be absorbed.
It should also be understood that in order to optimize this color ~
effect, the walls 13, which define an included obtuse angle with top wall 14, ;
should be offset from the vertical by from about 10 to about 35, and pre-
ferably about 15 as shown in the drawing. This gives an included angle of
about 105. Too great an angle will result in most light passing through ;
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the top wall and completely missing the side walls and entering the room
directly.
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