(12) United States Patent
`Heller et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,896,522 B2
`Mar. 1, 2011
`
`US007896522B2
`
`7.360,923 B2 * 4/2008 Weber-Rabsilber et al. .. 362/241
`2005, OO18428 A1
`1/2005 Harvey
`2007/0017131 A1
`1/2007 Visotcky
`
`EP
`EP
`EP
`JP
`
`FOREIGN PATENT DOCUMENTS
`0829844 A2
`9, 1997
`08298.44 B1
`9, 1997
`0829844 A1
`3, 1998
`2008O15438 A
`1, 2008
`OTHER PUBLICATIONS
`International Search Report and Written Opinion (PCT/US2009/
`034681)—entire document.
`Automated translation of Publication EP0829844, Nov. 3, 1999,
`Germany.
`* cited by examiner
`Primary Examiner Anabel M Ton
`(74) Attorney, Agent, or Firm—Charles L. Warner; Bryan
`Cave LLP
`(57)
`
`ABSTRACT
`
`A plurality of lamp arrays (30A-30N) provide uniform light
`ing across the copy area of a billboard sign. The arrays (30)
`are arranged end-to-end horizontally along the length of the
`copy area. Each array (30) comprises a plurality of LEDs
`(34A-34N) and a plurality of lenses (36A-36M). The various
`lenses (36) direct and focus the light from the LEDs (34) at the
`various parts of the copy area So as to minimize dark and light
`spots. A “TOP set of LEDs preferably illuminates the top
`part of the copy area, a “MIDDLE set of LEDs preferably
`illuminates the middle of the copy area, and “FILLER LEDs
`preferably serve to illuminate the bottom of the copy area.
`The lamp arrays are preferably mounted to a catwalk (14) at
`the bottom of the billboard.
`15 Claims, 13 Drawing Sheets
`
`(54) FRONTAL ILLUMINATION OF A SURFACE
`USING LED LIGHTING
`
`(75) Inventors: Todd R. Heller, Marietta, GA (US);
`Dewey T. Pitts, Marietta, GA (US)
`
`(73) Assignee: Formetco, Inc., Duluth, GA (US)
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 92 days.
`
`(21) Appl. No.: 12/389,871
`(22) Filed:
`Feb. 20, 2009
`(65)
`Prior Publication Data
`US 2009/0290338A1
`Nov. 26, 2009
`
`Related U.S. Application Data
`(60) Provisional application No. 61/029,952, filed on Feb.
`20, 2008.
`
`(51) Int. Cl.
`(2006.01)
`G09F 3/02
`(52) U.S. Cl. .................. 362/249.02: 362/235; 362/812;
`362/249.01; 362/231; 362/244; 40/541
`(58) Field of Classification Search ................. 362/800,
`362/231, 235, 244, 812, 249.01, 249.02:
`40/541–562
`See application file for complete search history.
`References Cited
`U.S. PATENT DOCUMENTS
`4,843,527 A
`6, 1989 Britt ...........................
`4,849,864 A
`7, 1989 Forrest ....................... 362,225
`6,510,633 B1
`1/2003 Bledsoe
`
`(56)
`
`
`
`Page 1 of 20
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`3ON
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`1.
`FRONTAL, ILLUMINATION OF A SURFACE
`USINGLED LIGHTING
`
`US 7,896,522 B2
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`PRIORITY CLAIM
`
`This application claims the priority of U.S. Provisional
`Patent Application 61/029,952 filed on Feb. 20, 2008, entitled
`“Frontal Illumination Of A Surface Using Led Lighting” by
`Todd R. Heller and Dewey T. Pitts. The entirety of the above
`provisional application is hereby incorporated herein by ref
`
`10
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`CCC.
`
`BACKGROUND OF THE INVENTION
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`1. Field of the Invention
`The present invention generally relates to lighting of bill
`boards, signs, buildings, and other structures and, more par
`ticularly, relates to front illumination of surfaces using light
`emitting diodes (LEDs).
`2. Description of the Related Art
`Historically, light fixtures providing front illumination of
`large advertising billboards have utilized various types of
`illumination sources, including electro-florescent tubes and
`flood lights (incandescent, high energy discharge, projection
`lamps). The illumination source is enclosed in a fixture which
`is mounted on an extended arm, and the extended arm posi
`tions the illumination source, also referred to as a light source,
`far enough away from the billboard face to illuminate the
`image area (or "copy area') for viewing in low light condi
`tions. Typically, because of the beamwidth limitations of the
`light source, two or more light fixtures are needed to illumi
`nate the copy area. The number of light fixtures needed thus
`depends upon the height and width of the copy area and the
`beamwidth of the light source. Also, in order to provide the
`desired dispersion of the light from the light sources, and to
`35
`provide for relatively even illumination from top to bottom of
`the copy area, the light sources have to be set back from the
`billboard face, typically 6 to 8 feet. The fixture mounting
`system is typically attached to the billboard support structure,
`either at or near the top of the bottom of, or both the top and
`the bottom of the billboard face. The fixture mounting system
`therefore typically extends the light fixture in front of the
`billboard face. The mounting device for each fixture typically
`consists of a metal tube, arm, or conduit which is mounted to
`the billboard structure, and which extends out approximately
`6 to 8 feet, the light source typically being attached at or near
`the end of the fixture.
`A larger number of light sources provides for more even
`illumination of the copy area, but generally results in higher
`costs, more physical structures, higher wind loading, and
`50
`more maintenance issues. Conversely, a lower number of
`light sources results in lower cost, fewer physical structures,
`lower wind loading, and fewer maintenance issues, but
`increases the likelihood that there will be noticeable and
`undesirable differences between better lit (lighter) areas and
`more poorly lit (darker) areas. As a compromise between
`these opposing goals and choices, a typical installation may
`use only a few light sources, spaced at intervals of 8 to 12 feet.
`To compensate for using a small number of light sources, the
`light sources are generally wide-angle light sources, so that
`the fields of illumination provided by the light sources over
`lap somewhat, thereby reducing the contrast between the
`differently-illuminated areas. The use of wide angle light
`Sources, however, brings on other problems such as, but not
`limited to, (1) inefficiency because the use of wide-angle light
`Sources causes a substantial amount of the light emitted to be
`spread outside the borders of the copy area; (2) undesired heat
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`generation because more light output, and therefore more
`energy, is required so that the light which strikes the copy area
`is of sufficient intensity to properly illuminate the copy area;
`and (3) light pollution problems because the light which does
`not strike the copy area contributes to night sky light pollu
`tion. Night sky pollution has become such a severe problem in
`many large cities that only the brightest stars are visible at
`night.
`Simply replacing the current light sources with LED light
`Sources would seem to be a solution but, in reality, is not a
`solution because of several problems: (1) a large number of
`LEDs is required to provide the desired illumination, (2) the
`optics and lensing required to illuminate the copy area suffi
`ciently is very complex, (3) the heat generated by a large
`number of LEDs in close proximity or clustered together
`causes the LEDs to quickly overheat and fail, and (4) cost,
`windloading, esthetic, maintenance, and other consider
`ations. Thus, neither simply replacing conventional light
`Sources with clustered LEDs, nor adding more projecting
`fixtures with fewer LEDs in a fixture, are viable options.
`BRIEF DESCRIPTION OF THE DRAWING
`
`FIG. 1 is an illustration of a billboard and shows the bill
`board face, the catwalk, and one possible LED lamp location.
`FIG. 2 is an illustration of a billboard and shows the bill
`board face, the catwalk, and another possible LED lamp
`location.
`FIG. 3 is an illustration of a billboard and shows the bill
`board face, the catwalk, another possible LED lamp location,
`and the preferred light dispersion characteristic.
`FIG. 4 is an illustration of one embodiment of a lamp array.
`FIG. 5 is an illustration of another embodiment of a lamp
`array.
`FIG. 6 is a side elevation cutaway view of an embodiment
`of a lamp array, and shows a typical position for the power
`supply and an individual LED cell.
`FIGS. 7 and 8 are photographs of an embodiment of a lamp
`array and show LED cells, both with and without optical
`lenses.
`FIGS. 9 and 10 are photographs of an embodiment of a
`lamp array and show the protective cover in place.
`FIGS. 11A-11E are illustration of various LED cell con
`figurations and various optical lensing arrangements.
`FIG. 12 is a photograph showing the light distribution
`provided by the LED lamp array of one embodiment.
`FIG. 13 is a photograph illustrating one method of con
`necting lamp arrays.
`
`DETAILED DESCRIPTION
`
`FIGS. 1-3 illustrate embodiments of various billboard
`installations and some location possibilities for LED lamp
`arrays. FIG. 1 is an illustration of one embodiment of a
`billboard 10 and shows the billboard face 12, the catwalk 14,
`and one possible location 16 for lamp arrays 30A-30N. FIG.
`2 is an illustration another embodiment of a billboard 10, and
`shows the billboard face 12, the catwalk 14, and another
`possible location 16 for the lamp arrays 30. FIG. 3 is an
`illustration of another embodiment of a billboard 10 and
`shows the billboard face 12, the catwalk 14, another possible
`location 16 for the lamp arrays 30, and the preferred light
`dispersion characteristic 20.
`The front illuminated sign has a plurality of LED lamp
`arrays 30A-30N, also referred to herein as light fixtures,
`preferably mounted to the service access catwalk 14 kickrail,
`and parallel to the advertising sign face 12. An adjustable
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`mounting bracket 15 accommodates various relationships
`between the advertising sign face 12 and the location of the
`service access catwalk 14 toe and kick rails 14A, 14B, such as
`differences in the locations of the catwalk kickrails in rela
`tionship to the sign face. Each LED light fixture is preferably
`long and rectangular in shape, and has either a single row or
`multiple rows of LED lamps. The fixtures are mounted on the
`service access catwalk kickrail, running horizontally along
`most of the length of the kickrail. Optical lens on the LED
`lamps selectively and purposefully distribute light vertically
`and horizontally across the copy area. Preferably, different
`lens with different light distribution patterns are used for the
`various LEDs. Even spacing of LED lamps, placed horizon
`tally along the catwalk kickrail, and directed towards the face
`of the billboard, results in consistent illumination of the copy
`aca.
`The illustrated embodiments provide a visually appealing
`method of illuminating the copy area of a billboard face from
`the front. There are no protruding light fixtures at the top or
`the bottom of the billboard. There is no need to obtain
`extended property line set back permission to accommodate
`the protruding light fixtures because the LED lights prefer
`ably occupy the same latitudinal space as the catwalks present
`on most billboards. Such catwalks are typically present to
`provide access for installation and changing of the advertising
`message, changing light bulbs, general servicing of the bill
`board, etc. More uniform horizontal illumination can be
`obtained as a result of evenly spacing LED fixtures along the
`catwalk kickrail, as opposed to adding and positioning pro
`truding light fixtures. In addition to providing for more even
`illumination, evenly spacing LED fixtures along the catwalk
`kickrail eliminates the need for large clusters of LEDs. LED
`fixtures, especially those intended to be direct replacements
`35
`for conventional light fixtures typically have large clusters of
`LEDs, which generate excessive heat build-up, resulting in
`premature LED failure. The use of the evenly spaced hori
`Zontal LED fixtures described herein provides for less power
`consumption, longer operating lifetimes, cooler operating
`temperatures, and considerably smaller fixtures than flood
`lights, electro-fluorescent tubes, or clustered LED fixtures.
`The illustrated embodiments provide for front illumination
`of advertising billboards and other vertical surfaces by using
`a plurality of horizontally oriented, preferably evenly spaced,
`LED light fixtures which are mounted to the service access
`catwalk kickrail parallel to the billboard or sign face.
`The illustrated embodiments also provide for an efficient
`layout of the LEDs, which simplifies cooling and efficiently
`distributes light in order to illuminate the copy area over a
`long horizontal distance. The LED fixtures are preferably
`evenly-spaced horizontally along the front of the sign face,
`and are preferably mounted in one, two, or three rows to avoid
`the build-up of heat, which buildup can reduce LED longev
`ity. A buildup of heat is typical of spotlight-type fixtures,
`including cluster LED fixtures.
`In addition, lamp arrays 30A-30N may be stacked so as to
`achieve more luminosity, and the rows may be offset from one
`another so as to achieve a more uniform illumination across
`the copy area.
`FIGS. 4-6 illustrate embodiments of various LED lamp
`array configurations. FIG. 4 is an illustration of one embodi
`ment of a lamp array 30 and shows a housing 32, a plurality of
`LEDs 34A-34N and a plurality of lens elements 36A-36M,
`where M is less than or equal to N, and, preferably, a cover 38
`to protect the LEDs 34 and lens 36 from the environment.
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`4
`FIG. 5 is an illustration of another embodiment of a lamp
`array 30 and shows a housing 32 and, preferably, a cover 38.
`The LEDs 34 and lens 36 are present but are not shown in this
`view.
`FIG. 6 is a side elevation cutaway view of the embodiment
`of the lamp array 30, such as the embodiment of FIG. 4, and
`shows the housing 32, a typical position for the power Supply
`40, and one LED 34/lens 36 combination.
`FIGS. 7-10 are photographs of exemplary lamp arrays 30.
`FIG. 7 shows an exemplary embodiment of a lamp array 30
`with an LED cell 34 covered by an optical lens 36. FIG. 8
`shows an exemplary embodiment of a lamp array 30 with an
`LED cell 34 which is not covered by an optical lens.
`FIGS. 9 and 10 show an exemplary embodiment of a lamp
`arrays 30 from two different perspectives, and show the pro
`tective cover 38 in place.
`As shown in FIGS. 1-3, the lamp arrays 30A-30N are lined
`up, end to end, at the desired position with respect to the
`catwalk 14, some but not all of which positions are shown. As
`can be seen, all LEDs 34 of the lamp arrays 30 preferably lie
`along the same line or axis, and are generally evenly spaced
`along the length of the catwalk 14. The lamp arrays 30 are
`preferably mounted just outside the catwalk area 14, which
`provides for ease of maintenance, Such as replacing a cracked
`protective cover 38.
`FIGS. 11A-11E illustrate some exemplary LED cell 34
`configurations for a lamp array 30. The LEDs 34 are spaced
`approximately 4 inches apart, which distance is preferred, but
`is not critical. The spacing is based on a tradeoff between, for
`example, the acceptable difference in the illumination levels
`in adjacent or even non-adjacent sections of the copy area, the
`minimum amount of lighting required, and the cost tradeoffs
`between higher power, but fewer, LEDs, and fewer lens,
`Versus lesser power, but more, LEDs, and more lens, etc.
`FIG. 11A illustrates an embodiment wherein lenses 36 are
`used on all of the LEDs 34. The various lenses 36 may be the
`same type or may be different types depending upon the
`uniformity of illumination desired or acceptable, color(s)
`desired, cost considerations, etc.
`It will be appreciated that light from a light source spreads
`as the light gets farther away from the light Source, so an area
`at one distance will receive a different amount of light than the
`same size area at a different distance. Further, it will be
`appreciated that a Surface which receives light from a light
`source shining directly at the surface will have a higher level
`of illumination per area of Surface than if that same Surface
`were turned at an angle to the light source. To compensate for
`these effects, for example, when the LED arrays are mounted
`toward the bottom of the billboard face such as on the cat
`walk, then more of the light is directed toward the upper
`portion of the copy area, because the upper portion is farther
`away from the LED arrays than the bottom portion and is at a
`greater angle with respect to the LED arrays than the bottom
`portion.
`FIG. 11B shows an embodiment wherein different lenses
`36 are used on some of the LEDs 34 and, preferably, no lenses
`are used on other LEDs 34. The designations “TOP’.
`“MIDDLE, and “FILLER” indicate the general vertical
`position on the copy area where the light from that particular
`LED 34 strikes the copy area. For example, for a billboard
`which has a copy area height of approximately 14 feet, a TOP
`area is preferably, but not necessarily, an oval area, approxi
`mately 2.5 feet high by 5 feet wide, the center of this TOP area
`being approximately 1.25 feet from the top edge of the copy
`area. A MIDDLE area is preferably, but not necessarily, a
`circular area, approximately 5 feet high by 5 feet wide, the
`center of this MIDDLE area being approximately 7 feet from
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`the top edge of the copy area. Although the TOP and
`MIDDLE areas could overlap, an overlap is not necessary so,
`in this embodiment, these areas do not overlap. It will be
`appreciated that the illumination outside of an area does not
`abruptly fall to zero outside of the area, but tapers off. Thus,
`a TOP position LED will provide some illumination outside
`of the TOP area, and a MIDDLE position LED will provide
`some illumination outside of the MIDDLE area. These out
`side-area illuminations therefore combine and enhance the
`uniformity of the illumination.
`A “FILLER' (or “BOTTOM) area is preferably, but not
`necessarily, approximately the bottom half of the copy area,
`Such as from the bottom edge of the copy area to approxi
`mately 9 feet from the bottom edge of the copy area. The
`FILLER area may be determined by focusing the light output
`from a FILLER LED, such as by using a lens, or may be
`determined by the characteristics of the particular LED
`device used. Although the MIDDLE and FILLER areas could
`overlap, an overlap is not necessary So, in this embodiment,
`these areas do not overlap. It will be appreciated, as men
`tioned above, that the illumination outside of an area does not
`abruptly fall to zero outside of the area, but tapers off.
`The TOP and MIDDLE areas are obtained by the use of
`focusing lenses and, in one embodiment, the focusing lens for
`a TOPLED has a beamwidth of 23 degrees by 50 degrees, and
`the focusing lens for a MIDDLE LED has a beamwidth of 45
`degrees. The FILLER LED preferably, but not necessarily,
`does not use a focusing lens. As used herein, the term “focus’
`is not limited to the narrowing of a beam of light from an LED
`but also includes broadening of a beam and adjusting the
`30
`pattern of a beam.
`In operation of a preferred embodiment, the TOP LEDs
`will illuminate the uppermost portions of the copy area. Pref
`erably, the illumination footprints provided by the TOPLEDs
`in the same lamp array will overlap, and the illumination
`35
`footprints provided by the TOP LEDs in adjacent arrays will
`overlap. The MIDDLE LEDs will illuminate the middle por
`tions of the copy area. Also, preferably, the illumination foot
`prints provided by the MIDDLE LEDs in the same lamp array
`will overlap, the illumination footprints provided by the
`40
`MIDDLE LEDs in adjacent arrays will overlap. The FILLER
`LEDs preferably illuminate at least the bottom portion of the
`copy area. Preferably, the illumination footprints provided by
`the FILLER LEDs in the same lamp array will overlap, and
`the illumination footprints provided by the FILLER LEDs in
`adjacent arrays will overlap. The overlap, or near overlap,
`between different footprints serves to make the illumination
`more uniform across the billboard and to reduce contrast
`between adjacent areas. Too little overlap can cause darker
`areas to appear, while too much overlap can cause brighter
`areas to appear, as well as increasing the cost of operation.
`FIG. 11C is an illustration of one LED cell configuration,
`such as might be used in FIGS. 11A and 11B, but without the
`lenses.
`FIGS. 11D and 11E show two alternative LED cell con
`figurations wherein the LEDs are grouped. One situation in
`which these configurations may be usedis, for example, when
`additional lighting is required so that the billboard face can be
`seen from a greater distance or in conditions other than near or
`total darkness. Another situation in which they may be used
`is, for example, to provide different colors or color effects.
`For example, all LEDs in a group may have the same color
`(but preferably different lens), and different groups may have
`different colors. As another example, the LEDs in a group
`may have different colors (and preferably similar or identical
`lens), and different groups may have lens with different char
`acteristics.
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`In one embodiment, the LEDs are type XlampTM, XR-E
`manufactured by CreeTM of Durham, N.C., and have an output
`of 100 Lumens at 350 milliamps (ma). These LEDs are rated
`at a current input of up to 1000 ma and, in one embodiment,
`the current input is 95.0 ma, which provides a light output of
`180 Lumens. In another embodiment, the LEDs are type
`XLamp 7090 XR, also manufactured by Cree.
`In one embodiment, such as when the above-mentioned
`Cree LEDs are used, the lens is an “FC Lens', sold by FraenTM
`Corporation, Reading, Mass. In another embodiment, the lens
`is a “CRS Square Lenses”, for CREE XR-E LEDs, sold by
`Marubeni America TM Corporation, Santa Clara, Calif. In one
`embodiment, the lens used for the “TOP position LEDs is a
`type CRS-O manufactured by Ledil OyTM, Salo, Finland,
`which has a vertical beamwidth of 28 degrees and a horizontal
`beamwidth of 12 degrees, and the lens used for the
`“MIDDLE” position LEDs is a type FC-W2-XR79-HRF
`manufactured by Fraen Corporation, and has a beamwidth
`(horizontal and Vertical) of 41 degrees.
`In another embodiment, rather than there being a single
`row of LEDs in a lamp array 30, there are two or more rows of
`LEDs in an array. The LEDs in the different rows may be in a
`vertical column, or they may be offset, if desired, so as to
`further and more evenly distribute the light shining on the
`copy area. For example, FIG. 11D shows a lamp array which
`has two rows of LEDs in a vertical column, and FIG. 11E
`shows a lamp array which may be considered to have three
`rows, the center row being offset horizontally from the other
`two rows. Other embodiments are also possible such as, for
`example, where the top row in FIG.11D is offset, with respect
`to the bottom row, by one-half of the distance between the
`elements in the bottom row.
`Although the embodiments are depicted on billboards
`which have catwalks, the LED arrays can also be used on
`billboards which do not have catwalks. One could use, for
`example, a plurality of mounting arms to Support the arrays.
`One could also, for example, provide a railing, set out from
`the bottom of the billboard, and held in place by a plurality of
`mounting arms, and fasten the arrays to the railing. Also,
`although the embodiments shown have the LED arrays
`mounted toward the bottom of the billboard, pointing gener
`ally upwardly, the LED arrays can, instead, be mounted
`toward the top of the billboard, and generally pointing down
`ward. Top mounting of the arrays may be accomplished, for
`example, by a plurality of mounting arms as mentioned
`above, or by a railing set out from the top billboard and held
`in place by a plurality of mounting arms. Also, if there are two
`billboards which are stacked, then the arrays could be
`mounted to the catwalk of the upper billboard and, in this
`case, the catwalk on the upper billboard may serve for mount
`ing of the light arrays for both the upper billboard and the
`lower billboard. In addition, if exceptional uniformity of illu
`mination is desired, or if exceptional luminance is desired,
`then two sets of LED arrays could be used, one mounted
`toward the bottom of the billboard, pointing generally
`upwardly, and the other mounted toward the top of the bill
`board, and generally pointing downward.
`For convenience of discussion below, it is assumed that the
`copy area has a size of 12 feetx24 feet. Thus, the copy area
`could be considered to be a 12 foot by 24 foot matrix of light
`surfaces. Also for convenience, Table I and Table II have both
`been broken into two table segments, with the top segment of
`the table representing the left one-half of the copy area, and
`the bottom part representing the right one-half of the copy
`aca.
`Table I shows the illumination across a 12 foot by 24 foot
`panel, which is illuminated by a typical four-projection arm
`
`Page 17 of 20
`
`

`

`US 7,896,522 B2
`
`10
`
`15
`
`30
`
`35
`
`7
`and light source array. The total power provided to the four
`High Intensity Discharge lamps (HID) is 432 watts (3.6amps
`at 120VAC), and the four arrays produce an illumination of
`42,000 Lumens. The panel is divided into 1 foot squares, but
`measurements were not taken on the leftmost, rightmost,
`topmost, or bottom most squares. Accordingly, measurements
`were conducted on 220 (10x22) squares. The numbers show
`the illumination in foot-candles for each square and are actual
`measurements, except that the values for squares A6-A22,
`B6-B22, and C16-C22 are estimates. From this, it can be seen
`that the total copy area illumination is 11152 footcandles, the
`average illumination is 50.60 footcandles, and the low and
`high illuminations are 16 and 124 footcandles, respectively.
`As the arrays produce 42000 lumens, and only 11152 lumens
`strike the board, this means that up to 30848 lumens are not
`used, contributing nothing to the illumination of the copy
`area, but contributing to night sky pollution. In other words,
`only about 26.55% of the illumination strikes the copy area,
`and the other 73.45% is effectively wasted.
`Table II similarly shows the illumination across a 12 foot
`by 24 foot panel, which is illuminated by an embodiment
`using LEDs. The total power provided to the LEDs is 240
`watts (2.0 amps at 120 VAC), and the LEDs produce an
`illumination of 13,500 Lumens. The numbers show the illu
`mination in foot-candles for each square and are actual mea
`25
`Surements, except that the values for squares A6-A22,
`B6-B22, and C6-C22 are estimates. From this, it can be seen
`that the total copy area illumination is 10747.6 footcandles,
`the average illumination is 48.85 footcandles, and the low and
`high illuminations are 12.6 and 99 footcandles, respectively.
`As the arrays produce 13500 lumens, and 10747.6 lumens
`strike the board, this means that only 2752.4 lumens are not
`used. In other words, about 79.61% of the illumination strikes
`the desired areas of the copy area, and only 20.39% is wasted.
`Therefore, the efficiency of the LED fixture, as compared
`to the High Density fixture, has been increased almost three
`fold, from 26.55% to 79.61%. Further, the power consump
`tion has been reduced by over 40% but the total light striking
`the copy area has decreased by less than 4%.
`
`8
`FIG. 12 is a photograph showing the light distribution
`provided by the LED lamp array of one embodiment.
`FIG. 13 is a photograph illustrating one method of con
`necting lamp arrays 30 in an end-to-end configuration. The
`lamp arrays 30 have end caps 40, and are held together by
`mounting hardware 42. Such as, but not limited to, a bolt and
`a nut. The method of connecting the lamp arrays 30 is not
`critical and other techniques may be used.
`
`TABLE I
`
`HID LIGHTING
`
`1
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`8 9 10 11
`
`18
`A.
`19
`B
`C 2O
`D 19
`E
`19
`F
`17
`G 16
`H
`17
`I
`19
`J
`18
`
`21
`24
`26
`25
`26
`24
`2O
`21
`22
`23
`
`23
`28
`33
`36
`35
`33
`29
`27
`29
`28
`
`26
`31
`39
`46
`45
`49
`41
`35
`35
`38
`
`28
`36
`43
`51
`60
`62
`61
`48
`44
`41
`
`28
`37
`46
`57
`67
`73
`72
`66
`S4
`49
`
`29 32 32 31 30
`36 39 41 40 38
`46 48 SO SO 49
`58 57 60 61 58
`72 69 69 70 67
`78 82 80 80 77
`79 85 93 100 103
`73 83 101 114 124
`69 82 98 107 109
`47 60 82 95 86
`
`12
`
`13
`
`14
`
`15
`
`16
`
`17
`
`18 19 20 21 22
`
`30
`A.
`38
`B
`C 49
`D 58
`E
`67
`F
`77
`G 103
`H 124
`I
`109
`J
`86
`
`31
`40
`50
`61
`70
`8O
`100
`114
`107
`86
`
`32
`41
`50
`60
`69
`8O
`96
`101
`98
`95
`
`32
`39
`48
`57
`69
`82
`85
`83
`82
`82
`
`29
`36
`46
`58
`72
`78
`79
`73
`69
`60
`
`28
`37
`46
`57
`67
`73
`72
`66
`S4
`47
`
`28 26 23 21 18
`36 31
`28 24 19
`43 39 33 25 20
`51 46 36 25 19
`60 4S 3S 26 19
`62 49 33 24 17
`61 41 29 20 16
`48 35 27 21 17
`44 3S 29 22 19
`49 41 38 26 23
`
`TABLE II
`
`LED LIGHTING
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`8
`
`9
`
`10
`
`11
`
`16.5
`19.9
`25.9
`33.8
`41.7
`39.1
`27.7
`21.3
`17.6
`13
`
`18
`21.5
`29.9
`39.3
`50.7
`SO.1
`38
`33.8
`30.3
`2O
`
`31.6 31.6 31.6 31.6 31.6 31.6 31.6
`25
`19
`39.5
`39.5
`39.5
`39.5
`39.5
`39.5
`39.5
`24.3 30
`32.4 39.S. 49
`49
`49
`49
`49
`49
`49
`44.6 51.8
`60.7 62
`66
`60
`50
`57
`64
`53.8 57
`71.7
`71
`71
`62
`53
`65
`76
`59.2
`65.6 74S 80.1
`79
`65
`60
`76
`83
`50
`62
`70
`82
`84
`70
`66
`83
`92
`43.6 53.1
`63.2 77
`84
`67
`63S 87.3
`94.1
`41.8 45.8 47.6 54
`57
`8O
`48
`69
`68
`26
`27
`27
`29
`29
`27
`29
`34
`37
`
`12
`
`13
`
`14
`
`15
`
`16
`
`17
`
`18
`
`19
`
`2O
`
`21
`
`22
`
`31.6
`39.5
`49
`63
`72
`78
`87
`99
`71
`35
`
`31.6
`39.5
`49
`55
`61
`65
`71
`70.1
`58
`32
`
`16.5
`18
`19
`31.6 31.6 31.6 31.6 31.6 25
`243 215 19.9
`39.S.
`39.S.
`39.S.
`39.S.
`39.S 30
`49
`49
`49
`49
`49
`39S 32.4 29.9 25.9
`57
`64
`62
`53
`46
`45
`44
`34
`16.5
`65
`68
`66
`58
`51
`53
`50
`40
`17
`71.2 74
`73
`64
`53
`56
`57
`41
`18
`8O
`81
`8O
`72
`65
`63
`64
`49
`17.8
`82
`84
`78
`69.9
`66.8
`6S.S
`65.1
`47.9
`18.6
`59
`60
`61
`57
`58
`56
`S4
`38
`16
`31
`34
`34
`34
`35
`37
`34
`25
`12.6
`
`Page 18 of 20
`
`

`

`It will be appreciated that the individual LEDs may be
`individually focused onto the copy area at the desired location
`and with the desired beamwidth. It will also be appreciated
`that if top mounting of the light array is desired, then some
`mounting mechanism must be provided to replace the catwalk
`used for bottom mounting of the light array. Even in Such a
`case, however, the light array will still be closer to the copy
`area than in conventional technology, and there will not be the
`long projection arms used by conventional technology.
`The housing may be secured to the catwalk, or to another
`available mounting Surface, by any con