Fluorescent lighting fixture

A lighting fixture consisting of a downwardly opening housing having a plurality of fluorescent lamps mounted therein, a louver assembly substantially closing the open bottom of the housing and dividing its area into vertically open cells only certain of which receives light from each of the lamps, the louvers being of sufficient vertical height to restrict light passing directly through the cells to a restricted primary area of brighter illumination in the room below, and a translucent light-diffusing panel covering the cells of the louver assembly receiving light from each of the lamps. The lamps may be selected to emanate light of respectively different colors, and both the louvers and the light-diffusing panels may be of selectively different tints and colors, so as to impart a novel, decorative appearance to the louver assembly when viewed from outside of the primary lighting area.

This invention relates to new and useful improvements in fluorescent light 
fixtures, and has particular reference to such fixtures adapted for use at 
ceiling level, for illuminating room areas therebeneath. It also has 
adaptability to light fixtures in which the lamps are of other than the 
fluorescent type. In general, objects of the invention include the 
efficiency of the room lighting, for example in limiting the room area 
subjected to the primary or brightest lighting effect, to provide bright 
illumination for a given work station or the like with relatively dim 
light being supplied to areas outside of that work station, and also the 
improvement of the appearance of the fixture, especially when viewed from 
outside the area of primary illumination mentioned above, by the novel use 
of color. 
More specifically, one object of the present invention is the provision of 
a lighting fixture including a downwardly opening housing carrying a 
plurality of fluorescent lamp tubes in the upper portion thereof, a louver 
assembly disposed in the lower opening of said housing and comprising a 
gridwork of vertical-walled cells each of which receives light principally 
from only one of said lamps, and a plurality of translucent 
light-diffusing panels overlying the top of said louver assembly to 
provide even illumination of all of the louver cells. The louvers are of 
substantial vertical height, whereby to direct the light emerging from the 
lower side thereof more directly downwardly than would be the case if the 
louvers were not used. This provides a primary room area directly beneath 
the fixture with a higher degree of illumination, while reducing 
illumination of surrounding areas, where bright illumination might be 
objectionable to other occupants of the room. 
Another object is the provision of a lighting fixture of the character 
described in which said louver assembly is vertically adjustable in said 
housing, relative to the fluorescent lamps. This provides for adjustment 
of the size of the primary area of bright illumination, as may be desired. 
A further object is the provision of a lighting fixture of the character 
described in which the fluorescent lamps themselves may be selected to 
emanate light of different colors, in which the light-diffusing diffusing 
panels are tinted so that each transmits light of a different color, and 
in which the louvers forming the cell walls are painted or otherwise 
finished in any desired color or combination of colors. While the lamps 
and the light-diffusing panels usually must be selected to transmit light 
of sufficient intensity and suitable color for proper illumination in the 
primary area, although substantial variation is permissable even in this 
area, the coloring of the louvers imparts a distinctly novel and 
decorative appearance to the fixture, especially when viewed from outside 
the primary area. By careful selection and intermingling of all of these 
variables, the fixture itself may become an integral and important element 
of room decor, harmonizing or contrasting attractively with any plans of 
the interior decorator. 
Other objects are simplicity and economy of construction, and efficiency, 
flexibility and reliability of operation.

Like reference numerals apply to similar parts throughout the several 
views, and the numeral 2 applies generally to the light fixture housing, 
comprising a downwardly opening, elongated trough 4 formed of sheet metal, 
which forms, at each longitudinal edge thereof, a shallow, downwardly 
opening cove 6 having an out-turned horizontal flange 8 at its extreme 
lower edge. Each end of the trough 4 is closed by a sheet metal end plate 
10 (see FIG. 3) having at its lower edge a sheet metal insert 12 which 
provides a cove 14 and flange 16 similar to, and at the same elevation as, 
cove 6 and flange 8 of the trough, but at the ends of the housing. Housing 
2 may be suspended from a permanent room ceiling by wires or any other 
suitable means, not shown, and drop-ceiling acoustical panels 18 may be 
supported on flanges 8 and 16, as shown and as well known in the art. 
A plurality (three shown) of fluorescent lamp tubes 20, or other electric 
lamps extend longitudinally in the upper portion of the housing, in evenly 
spaced relation across its width. Each lamp tube is engaged at each end 
(one end shown in FIG. 3), in a socket member 22 carried by a bracket 24 
fixed to the top of trough 4. A longitudinal hump 26 formed centrally in 
the top of trough 4, and a cover plate 28 applied to said trough 
immediately beneath said hump, provides a space 30 for containing any 
necessary electrical ballast, and for containing wires extending to the 
ends of the housing, and brackets 24 provide wire-ways to the individual 
sockets 22. However, said ballast and wiring are well known in the art, 
and are not shown, not being considered pertinent to the present 
invention. 
Normally disposed horizontally within the lower opening of housing 2, and 
with its edges engaging loosely within side coves 6 and end coves 14, is a 
rectangular door frame indicated generally by the numeral 32. If it does 
not reach fully into a cove 14, as shown in FIG. 3, an extension plate 34 
is attached thereto which extends outwardly sufficiently to engage in the 
cove, both to limit upward movement of the frame and to prevent downward 
escape of light which has not passed through the frame, in which the 
louver assembly to be described is mounted. Said door frame comprises a 
pair of side rails 36 and a pair of end rails 38. The side and end rails 
are preferably formed of extruded aluminum or the like, and as best shown 
in FIG. 7, are releasably joined at each corner of the frame by a 
horizontal screw 40 based in side rail 36 and threaded into a screw boss 
42 which is extruded integrally with the end rail 38. By the removal of 
the four screws 40, the frame may be disassembled. Along one of its side 
edges, door frame 32 is hinged to trough 4 for pivotal movement on an axis 
parallel to said edge by a pair of hinges 44, each of said hinges 
comprising an arm fixed at its inner end to the door frame and extending 
outwardly through a T-shaped hole 46 formed in the vertical wall of cove 
6, as best shown in FIGS. 4 and 5. The arm is provided at its outer end 
with a T-head 48 insertable through the top cross arm of hole 46, and 
turned downwardly to rest on trough flange 8 with the arm in the narrower 
upright portion of the hole. By lifting the frame slightly, T-head 48 may 
be retracted through the top cross arm of hole 46 to separate the door 
frame from the housing, when said door frame is inclined downwardly. The 
opposite side edge of the door frame is releasably secured in its 
corresponding cove 6 by a pair of latches each indicated generally by the 
numeral 50, and best shown in FIG. 6. Each latch comprises a bolt 52 
horizontally slidable in a keeper 54 fixed to the door frame, said bolt 
having an upstanding finger 56 projecting upwardly through a slot 58 
formed in the top horizontal wall of cove 6 and having a latch tooth 60 
operable to overlap said cove wall to secure the door frame in a 
horizontal position. Said bolt is biased toward its engaging position by a 
spring 62 disposed in carrier 54, but is movable to its release position 
by a manually accessible finger 64 fixed thereto. 
Carried within door frame 32 is a louver assembly designated generally by 
the numeral 66. Said assembly comprises a series of longitudinally 
extending louvers 68 and a series of transversely extending louvers 70, 
equally spaced to divide the area into a gridwork of identically shaped 
rectangular cells 72. All of the louvers are arranged with their planes 
disposed vertically. The louvers, at each of their points of intersection, 
are provided with slots 73 extending from their respectively upper and 
lower edges, as shown in FIG. 8, which interengage when the louvers are 
moved vertically into corresponding vertical alignment. Their lower edges 
are all coplanar, as are the upper edges of all of the transverse louvers, 
but the longitudinal louvers extend well above the upper edges of the 
transverse louvers, for a purpose which will presently appear. Each of 
lamps 20 is disposed above and midway between a successive pair of 
longitudinal louvers, and is parallel thereto, so as to illuminate 
principally only the longitudinal row of cells 72 directly therebeneath. 
The upward extension of the longitudinal louvers largely prevents and 
inhibits light from each lamp from reaching the adjacent row of cells 
illuminated by adjacent lamps, which as will appear may be emanating light 
of a different color. Each louver is provided at each end with at least 
one projecting "toy tab" 74 which is projected through a matching slot in 
the adjacent marginal louver and then twisted slightly, whereby to hold 
the louvers firmly in assembly. Each longitudinal row of cells 72 is 
covered by an elongated light-diffusing panel 76 resting on the upper 
edges of transverse louvers 70, being confined transversely between a 
successive pair of longitudinal louvers and secured against longitudinal 
movement by upstanding tabs 78 fixed to the endmost of transverse louvers 
70 and projecting upwardly therefrom. These panels may be of any desired 
tints, either identical or different, and are translucent but not 
transparent in the sense of being able to distinguish clear images 
therethrough, a surface thereof being roughened or irregular for this 
purpose. A popular form for this roughening is the formation of a surface 
thereof in very small projecting pyramidal points 80, as indicated in FIG. 
9. 
Louver assembly 66 is mounted in door frame 32 by means of a horizontal 
sheet metal angle 82 extending horizontally along the outer surface of 
each of the marginal louvers, as best shown in FIGS. 3 and 5. The vertical 
leg of each of said angles is secured to the marginal louver by a bolt 84 
(see FIG. 3) engaged in a vertical slot 86 of the louver. By loosening all 
of bolts 84, the louver assembly may be moved upwardly or downwardly 
relative to angles 82. The horizontal leg of each angle 82 projects 
outwardly into the adjacent rail of door frame 32, whereby the louver 
assembly is supported. The door frame rails are of inwardly opening 
C-channel form to receive the angle flanges, and are of substantial size 
to provide rigidity for the door frame, but each rail is provided with an 
internal flange 88 (see FIG. 5) for preventing excessive vertical movement 
of the horizontal angle flanges, which could result in rattling noises. 
In operation, it will be understood that fluorescent lamps 20 may be 
selected to emanate light of either the same or different colors. Such 
lamps are at present most commonly designated either "cool white", the 
light from which peaks in the shorter wave lengths adjacent the blue end 
of the visible spectrum, or "warm white", the light from which peaks in 
the longer wave lengths adjacent the red end of the visible spectrum. 
However, fluorescent lamps emanating light of other colors are or may soon 
become available. The light from each lamp illuminates principally only 
the longitudinal row of louver cells 72 directly therebeneath, through its 
corresponding light-diffusing panel 76, illumination of adjacent cell rows 
being largely inhibited and prevented by the upward extension of 
longitudinal louvers 68 well above the panels 76. The light-diffusing 
panels may also be of the same or selectively different color tints. Since 
most commonly it will be desired that the fixture supply a bright, full 
illumination at least in a primary area of the room directly beneath the 
fixture, the colors of the panels will ordinarily be light, such as light 
ambers, grays and the like. However, the fixture may also be used to 
provide relatively dim "mood" light, or more strongly colored light for 
use in rooms not requiring bright illumination, and in such cases as this 
the light-diffusing panels could be more brightly or darkly colored. Light 
passing through these panels is diffused to illuminate the vertical walls 
of the louvers evenly, and the louvers in turn reflect the light 
downwardly to the room area. The louvers may also be of the same or 
selectively different colors. Opposite sides of even a single louver may 
be of different colors, or even different sections of the same side of a 
louver. Since the louvers themselves will ordinarily be viewed only from 
points of the room outside of the area of primary bright illumination 
directly beneath the fixture, their color is relatively immaterial to 
efficiency of room illumination, and the louvers may thus be utilized as a 
room decorating element, with the colors thereof harmonizing, contrasting, 
or otherwise enhancing virtually any conceivable room decor. Other 
fixtures could be placed over any other area of the room which requires 
bright illumination. The selection of black or charcoal-colored louvers 
produces an effect in which the fixture may almost appear to be not 
lighted at all, from anywhere outside of the primary area of bright 
illumination. The louver surfaces may be polished and highly reflective, 
or may be of a dull or matte finish to be highly light-absorptive. Still 
further novel effects may be obtained by providing lamps 20 with wiring 
and switching means whereby said lamps may be energized either singly or 
in various combinations, as is already well known in the art. 
Light ray lines 90 in FIG. 2 and 92 in FIG. 3 indicate, when extended 
downwardly to the "living level" of the room, the span of the previously 
discussed primary area of bright illumination, since in this area light 
can reach the living level without being reflected from the louver 
surfaces. This restriction of said primary area is useful when the fixture 
is disposed over a work station of a room requiring bright illumination, 
while other areas of the room do not. This increases the room area from 
which the purely decorative appearance of the fixture may be viewed. Also, 
bearing in mind that while the light-diffusing panels 76 are not 
transparent, the lamps 20 above them still produce small areas of extreme 
brightness on the panels, visible from beneath the panels, which can 
reflect, for example, from the cathode ray tube readout screens of 
computers disposed in the room beneath. Such reflections are annoying and 
distracting to operators of the computers, and can sometimes obscure vital 
information displayed on the screens. With the present fixture, the 
computers can be placed outside of the primary illumination area, 
whereupon such reflections will not appear in the screens. The restriction 
of the room area subjected to bright illumination is accomplished by the 
substantial vertical width of the louvers 68 and 70, which is much greater 
than the thin "egg-crate" grills with which some fluorescent fixtures are 
already sometimes equipped, largely for the purpose of protecting the 
fluorescent lamps. In the present fixture, the effect may be increased by 
loosening bolts 84 and lowering the entire louver assembly relative to the 
lamps. Referring to FIGS. 2 and 3, it will be obvious that this lowering 
of the louvers will reduce the horizontal angle between ray lines 90 and 
92, and thus reduce the area of the room below being subjected to the 
brighter light. 
Thus it will be apparent that the structure described accomplishes the 
objects of the invention. The described fixture provides a primary area of 
bright illumination in a confined area of the room, while subjecting the 
remainder of the room to relatively subdued illumination. The dimensions 
of this primary area may be adjusted to a considerable extent. While the 
primary area might usually require bright illumination, it can be varied 
to any desired degree of relative dimness and color, to suit any "mood" or 
decor, or for use in rooms not requiring bright illumination, by the 
proper selection of lamps 20 to emanate light of different color makeup, 
and diffusion panels 76 of the desired color. When viewed from any part of 
the room outside of the primary area, the only illuminated portion of the 
fixture visible are the louvers themselves, which as described above may 
be of any desired color or combination of colors, thus constituting the 
fixture as a decorative ornament for the room, which may be varied as to 
color pattern to complement virtually any room decor. The "apparent" color 
of the louvers is a product not only of their own color, but also of the 
color of the light emanated by each lamp 20, the tint of the diffusion 
panels 76, and the reflectivity of the louvers. With the wide variability 
of each of these factors, altered either singly or in various 
combinations, the color combinations which may be produced are virtually 
infinite. 
While we have shown and described a specific embodiment of our invention, 
it will be readily apparent that many minor changes of structure and 
operation could be made without departing from the spirit of the invention 
.