United States Patent
`[19]
`[11] Patent Number:
`6,016,038
`
`Mueller et al.
`[45] Date of Patent:
`*Jan. 18, 2000
`
`USOO6016038A
`
`[54] MULTICOLORED LED LIGHTING METHOD
`AND APPARATUS
`
`[75]
`
`Inventors: George G. Mueller, Boston, Mass.;
`-
`IhorA' Lys’ PlttSburgh’ Pa‘
`[73] Assignee: Color Kinetics, Inc., Boston, Mass.
`
`*
`
`.
`.
`] Notice.
`
`[
`
`.
`.
`.
`This. patent issued on a continued pros-
`ecutlon application filed under 37 CFR
`1.53(d), and is subject to the twenty year
`patent
`term provisions of 35 U.S.C.
`5400(2).
`
`[21] Appl. No.: 08/920,156
`
`[22]
`
`Filed:
`
`Aug. 26, 1997
`
`Int. Cl.7 ..................................................... H05B 37/02
`[51]
`[52] US. Cl.
`.......................... 315/291; 315/312; 315/362;
`315/292
`[58] Field of Search ..................................... 315/291, 292,
`315/295, 300, 316, 302, 362, 312, 314,
`324, 307, 76, 297, 308, 209 R, DIG. 5
`
`[56]
`
`References Cited
`
`
`
`US PATENT DOCUMENTS
`
`..... 315/77
`7/1973 Drucker et al.
`3,746,918
`11/1981 Okuno ...............
`4,298,869
`340/782
`5/1982 Nishizawa et al.
`4,329,625
`.. 315/158
`.. 340/701
`1/1983 Kurahashi et a1.
`4,367,464
`...................... 315/316
`6/1983 Yamazaki et al.
`4,388,567
`...................... 315/296
`12/1983 Takahashi et al.
`4,420,711
`315/317
`11/1986 Nakai
`............
`4,625,152
`
`gfiggg 3:31;?........
`T335542:
`2:23;???
`4,887,074 12/1989 Simon et a1.
`........................... 340/782
`4,992,704
`2/1991 Stinson
`315/312
`5,003,227
`3/1991 Nilssen ..
`.. 315/324
`5,008,595
`4/1991 Kazar
`.. 315/178
`5,126,634
`6/1992 Johnson
`315/71
`3912:3513; 13/133: it“? etbal’ ““““l"""""""""" gig/3(1);
`5184114
`41993 stwlra am a a ‘ """"""""" 340201
`
`5,226,723
`7/1993 Chen .....
`362/241
`5,254,910 10/1993 Yang ....................................... 315/313
`
`
`
`........................... 315/313
`5,256,948 10/1993 Boldin et a1.
`..... 362/294
`5,282,121
`1/1994 Bornhorst et al.
`
`3/1994 Haraden ..................... 315/58
`5,294,865
`
`gagggafig 10/133: Eanhamomt 6: a1~ ~~~~~~~~~~~~~~~~~~~~ gig/:0:
`,
`,
`uc aco e a .
`........................
`12/1994 Horibata et a1.
`.
`..... 315/313
`5,374,876
`
`2/1995 Malita .................... 40/570
`5,388,357
`
`4/1995 Klinke et a1.
`. 362/249
`5,404,282
`
`4/1995 Sugden .......... 315/292
`5,406,176
`
`4/1995 Yoksza et a1.
`5,410,328
`345/82
`
`5/1995 Phares ..........
`.. 315/292
`5,420,482
`7/1995 Yang ....................................... 315/313
`5,436,535
`.
`.
`(L1st continued on next page.)
`FOREIGN PATENT DOCUMENTS
`
`0 752 632 A2
`0 752 632 A3
`2 640 791
`06043830
`2 176 042
`
`1/1997 European Pat. Off.
`8/1997 European Pat. Off.
`12/1988
`France .
`2/1994
`Japan .
`10/1986 United Kingdom .
`
`.
`.
`
`OTHER PUBLICATIONS
`Data Sheet LM140A/LM140/LM340A/LM7800C, National
`Semiconductor, Jan. 1995.
`Data Sheet DS2003/DS9667/DS2004, National Semicon-
`ductor, Dec. 1995
`Data Sheet DS96177, National Semiconductor, Feb. 1996.
`Data Sheet LM117/LM317A/LM317, National Semicon-
`ductor, May 1997.
`.
`.
`Prtmary Examzner—Don Wong
`Assistant Examiner—Wilson Lee
`Attorney, Agent, or Firm—Foley, Hoag & Eliot, LLP
`
`[57]
`ABSTRACT
`The systems and methods described herein relate to LED
`Systems capable of generating light, such as for illumination
`or display purposes. The light-emitting LEDs may be con-
`trolled by a processor to alter the brightness and/or color of
`the generated light, e.g., by using pulse-Width modulated
`signals. Thus, the resulting illumination may be controlled
`by a computer program to provide complex, predesigned
`patterns of light in virtually any environment.
`
`25 Claims, 6 Drawing Sheets
`
`fl
`
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`7324
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`22M
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`1
`Aoizh
`
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`
`
`
`
`
`454
`“4"
`344
`my :3?
`1Q
`
`
`
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`
`950
`
`
`
`
`
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`7980],990
`
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`
`300
`
`850
`
`HTC, Exhibit 1005
`
`HTC, Exhibit 1005
`
`

`

`6,016,038
`
`Page 2
`
`US. PATENT DOCUMENTS
`
`5,463,280 10/1995 Johnson .................................. 315/187
`
`5,504,395
`4/1996 Johnson et a1.
`315/71
`8/1996 Cho ........................................... 315/56
`5,545,950
`
`5,561,346
`5,575,459
`5,592,051
`5,751,118
`5,821,695
`
`10/1996 Byrne ...................................... 313/512
`11/1996 Anderson ................................ 362/240
`1/1997 Korkala
`315/210
`
`5/1998 Mortimer .....
`315/291
`10/1998 Vilanilam et a1.
`........................ 315/58
`
`HTC, Exhibit 1005
`
`HTC, Exhibit 1005
`
`

`

`US. Patent
`
`Jan. 18,2000
`
`Sheet 1 0f 6
`
`6,016,038
`
`
`
`HTC, Exhibit 1005
`
`HTC, Exhibit 1005
`
`

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`HTC, Exhibit 1005
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`

`

`US. Patent
`
`Jan. 18,2000
`
`Sheet 3 0f 6
`
`6,016,038
`
`<-
`
`O H
`
`TC, Exhibit 1005
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`HTC, Exhibit 1005
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`

`

`US. Patent
`
`Jan. 18, 2000
`
`Sheet 4 0f 6
`
`6,016,038
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`100
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`HTC, Exhibit 1005
`
`HTC, Exhibit 1005
`
`

`

`US. Patent
`
`Jan. 18,2000
`
`Sheet 5 0f 6
`
`6,016,038
`
`200
`
`
`
`200
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` 210
`
`|—|
`
`Fig. 7
`
`HTC, Exhibit 1005
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`HTC, Exhibit 1005
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`

`

`US. Patent
`
`Jan. 18,2000
`
`Sheet 6 0f 6
`
`6,016,038
`
`
`
`Fig. 9
`
`HTC, Exhibit 1005
`
`HTC, Exhibit 1005
`
`

`

`6,016,038
`
`1
`MULTICOLORED LED LIGHTING METHOD
`AND APPARATUS
`
`BACKGROUND OF THE INVENTION
`
`invention relates to providing light of a
`The present
`selectable color using LEDs. More particularly, the present
`invention is a method and apparatus for providing multicol-
`ored illumination. More particularly still, the present inven-
`tion is an apparatus for providing a computer controlled
`multicolored illumination network capable of high perfor-
`mance and rapid color selection and change.
`It is well known that combining the projected light of one
`color with the projected light of another color will result in
`the creation of a third color. It is also well known that the
`three most commonly used primary colors—red, blue and
`green—can be combined in different proportions to generate
`almost any color in the visible spectrum. The present inven-
`tion takes advantage of these effects by combining the
`projected light
`from at
`least
`two light emitting diodes
`(LEDs) of different primary colors.
`Computer lighting networks are not new. US. Pat. No.
`5,420,482, issued to Phares, describes one such network that
`uses different colored LEDs to generate a selectable color.
`Phares is primarily for use as a display apparatus. However,
`the apparatus has several disadvantages and limitations.
`First, each of the three color LEDs in Phares is powered
`through a transistor biasing scheme in which the transistor
`base is coupled to a respective latch register through biasing
`resistors. The three latches are all simultaneously connected
`to the same data lines on the data bus. This means it is
`impossible in Phares to change all three LED transistor
`biases independently and simultaneously. Also, biasing of
`the transistors is inefficient because power delivered to the
`LEDs is smaller than that dissipated in the biasing network.
`This makes the device poorly suited for efficient illumina-
`tion applications. The transistor biasing used by Phares also
`makes it difficult, if not impossible, to interchange groups of
`LEDs having different power ratings, and hence different
`intensity levels.
`US. Pat. No. 4,845,481, issued to Havel, is directed to a
`multicolored display device. Havel addresses some, but not
`all of the switching problems associated with Phares. Havel
`uses a pulse width modulated signal to provide current to
`respective LEDs at a particular duty cycle. However, no
`provision is made for precise and rapid control over the
`colors emitted. As a stand alone unit, the apparatus in Havel
`suggests away from network lighting, and therefore lacks
`any teaching as to how to implement a pulse width modu-
`lated computer lighting network. Further, Havel does not
`appreciate the use of LEDs beyond mere displays, such as
`for illumination.
`
`US. Pat. No. 5,184,114, issued to Brown, shows an LED
`display system. But Brown lacks any suggestion to use
`LEDs for illumination, or to use LEDs in a configurable
`computer network environment. US. Pat. No. 5,134,387,
`issued to Smith et al., directed to an LED matrix display,
`contains similar problems. Its rudimentary current control
`scheme severely limits the possible range of colors that can
`be displayed.
`It is an object of the present invention to overcome the
`limitations of the prior art by providing a high performance
`computer controlled multicolored LED lighting network.
`It is a further object of the present invention to provide a
`unique LED lighting network structure capable of both a
`linear chain of nodes and a binary tree configuration.
`It is still another object of the present invention to provide
`a unique heat-dissipating housing to contain the lighting
`units of the lighting network.
`
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`It is yet another object of the present invention to provide
`a current regulated LED lighting apparatus, wherein the
`apparatus contains lighting modules each having its own
`maximum current rating and each conveniently interchange-
`able with one another.
`
`invention to
`It is a still further object of the present
`provide a unique computer current-controlled LED lighting
`assembly for use as a general illumination device capable of
`emitting multiple colors in a continuously programmable
`24-bit spectrum.
`It is yet a still further object of the present invention to
`provide a unique flashlight, inclinometer, thermometer, gen-
`eral environmental indicator and lightbulb, all utilizing the
`general computer current-control principles of the present
`invention.
`
`Other objects of the present invention will be apparent
`from the detailed description below.
`
`SUMMARY OF THE INVENTION
`
`the invention herein comprises a pulse width
`In brief,
`modulated current control for an LED lighting assembly,
`where each current-controlled unit is uniquely addressable
`and capable of receiving illumination color information on
`a computer lighting network. In a further embodiment, the
`invention includes a binary tree network configuration of
`lighting units (nodes). In another embodiment, the present
`invention comprises a heat dissipating housing, made out of
`a heat-conductive material, for housing the lighting assem-
`bly. The heat dissipating housing contains two stacked
`circuit boards holding respectively the power module and
`the light module. The light module is adapted to be conve-
`niently interchanged with other light modules having pro-
`grammable current, and hence maximum light
`intensity,
`ratings. Other embodiments of the present invention involve
`novel applications for
`the general principles described
`herein.
`
`DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a stylized electrical circuit schematic of the light
`module of the present invention.
`FIG. 2 is a stylized electrical circuit schematic of the
`power module of the present invention.
`FIG. 3 is an exploded view of the housing of one of the
`embodiments of the present invention.
`FIG. 4 is a plan view of the LED-containing side of the
`light module of the present invention.
`FIG. 5 is a plan view of the electrical connector side of the
`light module of the present invention.
`FIG. 6 is a plan view of the power terminal side of the
`power module of the present invention.
`FIG. 7 is a plan view of the electrical connector side of the
`power module of the present invention.
`FIG. 8 is an exploded view of a flashlight assembly
`containing the LED lighting module of the present inven-
`tion.
`
`FIG. 9 is a control block diagram of the environmental
`indicator of the present invention.
`DETAILED DESCRIPTION
`
`The structure and operation of a preferred embodiment
`will now be described. It should be understood that many
`other ways of practicing the inventions herein are available,
`and the embodiments described herein are exemplary and
`not
`limiting. Turning to FIG. 1, shown is an electrical
`
`HTC, Exhibit 1005
`
`HTC, Exhibit 1005
`
`

`

`6,016,038
`
`3
`schematic representation of a light module 100 of the
`present invention. FIGS. 4 and 5 show the LED-containing
`side and the electrical connector side of light module 100.
`Light module 100 is self-contained, and is configured to be
`a standard item interchangeable with any similarly con-
`structed light module. Light module 100 contains a ten-pin
`electrical connector 110 of the general
`type.
`In this
`embodiment, the connector 110 contains male pins adapted
`to fit
`into a complementary ten-pin connector female
`assembly,
`to be described below. Pin 180 is the power
`supply. A source of DC electrical potential enters module
`100 on pin 180. Pin 180 is electrically connected to the
`anode end of light emitting diode (LED) sets 120, 140 and
`160 to establish a uniform high potential on each anode end.
`LED set 120 contains red LEDs, set 140 contains blue and
`set 160 contains green, each obtainable from the Nichia
`America Corporation. These LEDs are primary colors, in the
`sense that such colors when combined in preselected pro-
`portions can generate any color in the spectrum. While three
`primary colors is preferred, it will be understood that the
`present invention will function nearly as well with only two
`primary colors to generate any color in the spectrum.
`Likewise, while the different primary colors are arranged
`herein on sets of uniformly colored LEDs, it will be appre-
`ciated that the same effect may be achieved with single
`LEDs containing multiple color-emitting semiconductor
`dies. LED sets 120, 140 and 160 each preferably contains a
`serial/parallel array of LEDs in the manner described by
`Okuno in US. Pat. No. 4,298,869, incorporated herein by
`reference. In the present embodiment, LED set 120 contains
`three parallel connected rows of nine red LEDs (not shown),
`and LED sets 140 and 160 each contain five parallel con-
`nected rows of five blue and green LEDs, respectively (not
`shown). It is understood by those in the art that, in general,
`each red LED drops the potential in the line by a lower
`amount than each blue or green LED, about 2.1 V, compared
`to 4.0 V, respectively, which accounts for the different row
`lengths. This is because the number of LEDs in each row is
`determined by the amount of voltage drop desired between
`the anode end at the power supply voltage and the cathode
`end of the last LED in the row. Also, the parallel arrange-
`ment of rows is a fail-safe measure that ensures that the light
`module 100 will still function even if a single LED in a row
`fails, thus opening the electrical circuit in that row. The
`cathode ends of the three parallel rows of nine red LEDs in
`LED set 120 are then connected in common, and go to pin
`128 on connector 110. Likewise, the cathode ends of the five
`parallel rows of five blue LEDs in LED set 140 are con-
`nected in common, and go to pin 148 on connector 110. The
`cathode ends of the five parallel rows of five green LEDs in
`LED set 160 are connected in common, and go to pin 168
`on connector 110. Finally, on light module 100, each LED
`set is associated with a programming resistor that combines
`with other components, described below,
`to program the
`maXimum current through each set of LEDs. Between pin
`124 and 126 is resistor 122, 6.292. Between pin 144 and 146
`is resistor 142, 4.79. Between pin 164 and 166 is resistor
`162, 4.79. Resistor 122 programs maXimum current through
`red LED set 120, resistor 142 programs maXimum current
`through blue LED set 140, and resistor 162 programs
`maXimum current through green LED set 160. The values
`these resistors should take are determined empirically, based
`on the desired maXimum light intensity of each LED set. In
`the present embodiment, the resistances above program red,
`blue and green currents of 70, 50 and 50 MA, respectively.
`With the electrical structure of light module 100
`described, attention will now be given to the electrical
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`structure of power module 200, shown in FIG. 2. FIGS. 6
`and 7 show the power terminal side and electrical connector
`side of an embodiment of power module 200. Like light
`module 100, power module 200 is self contained. Intercon-
`nection with male pin set 110 is achieved through comple-
`mentary female pin set 210. Pin 280 connects with pin 180
`for supplying power, delivered to pin 280 from supply 300.
`Supply 300 is shown as a functional block for simplicity. In
`actuality, supply 300 can take numerous forms for generat-
`ing a DC voltage. In the present embodiment, supply 300
`provides 24 Volts through a connection terminal (not
`shown), coupled to pin 280 through transient protection
`capacitors (not shown) of the general
`type.
`It will be
`appreciated that supply 300 may also supply a DC voltage
`after rectification and/or voltage transformation of an AC
`supply, as described more fully in US. Pat. No. 4,298,869.
`Also connected to pin connector 210 are three current
`programming integrated circuits, ICR 220, ICB 240 and ICG
`260. Each of these is a three terminal adjustable regulator,
`preferably part number LM317B, available from the
`National Semiconductor Corporation, Santa Clara, Calif.
`The teachings of the LM317 datasheet are incorporated
`herein by reference. Each regulator contains an input
`terminal, an output terminal and an adjustment terminal,
`labeled I, O and A, respectively. The regulators function to
`maintain a constant maXimum current into the input terminal
`and out of the output terminal. This maXimum current is
`pre-programmed by setting a resistance between the output
`and the adjustment terminals. This is because the regulator
`will cause the voltage at
`the input terminal to settle to
`whatever value is needed to cause 1.25 V to appear across
`the fixed current set resistor, thus causing constant current to
`flow. Since each functions identically, only ICR 220 will
`now be described. First, current enters the input terminal of
`ICR 220 from pin 228. Of course, pin 228 in the power
`module is coupled to pin 128 in the light module, and
`receives current directly from the cathode end of the red
`LED set 120. Since resistor 122 is ordinarily disposed
`between the output and adjustment terminals of ICR 220
`through pins 224/124 and 226/126, resistor 122 programs
`the amount of current regulated by ICR 220. Eventually, the
`current output from the adjustment terminal of ICR 220
`enters a Darlington driver. In this way, ICR 220 and asso-
`ciated resistor 122 program the maXimum current through
`red LED set 120. Similar results are achieved with ICB 240
`and resistor 142 for blue LED set 140, and with ICG 260 and
`resistor 162 for green LED set 160.
`The red, blue and green LED currents enter another
`integrated circuit, IC1 380, at respective nodes 324, 344 and
`364. IC1 380 is preferably a high current/voltage Darlington
`driver, part no. DS2003 available from the National Semi-
`conductor Corporation, Santa Clara, Calif. IC1 380 is used
`as a current sink, and functions to switch current between
`respective LED sets and ground 390. As described in the
`DS2003 datasheet, incorporated herein by reference, IC1
`contains siX sets of Darlington transistors with appropriate
`on-board biasing resistors. As shown, nodes 324, 344 and
`364 couple the current from the respective LED sets to three
`pairs of these Darlington transistors,
`in the well known
`manner to take advantage of the fact that the current rating
`of IC1 380 may be doubled by using pairs of Darlington
`transistors to sink respective currents. Each of the three
`on-board Darlington pairs is used in the following manner as
`a switch. The base of each Darlington pair is coupled to
`signal inputs 424, 444 and 464, respectively. Hence, input
`424 is the signal input for switching current through node
`324, and thus the red LED set 120. Input 444 is the signal
`
`HTC, Exhibit 1005
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`HTC, Exhibit 1005
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`

`

`6,016,038
`
`5
`input for switching current though node 344, and thus the
`blue LED set 140. Input 464 is the signal input for switching
`current through node 364, and thus the green LED set 160.
`Signal inputs 424, 444 and 464 are coupled to respective
`signal outputs 434, 454 and 474 on microcontroller IC2 400,
`as described below. In essence, when a high frequency
`square wave is incident on a respective signal input, IC1 380
`switches current through a respective node with the identical
`frequency and duty cycle. Thus, in operation, the states of
`signal inputs 424, 444 and 464 directly correlate with the
`opening and closing of the power circuit through respective
`LED sets 120, 140 and 160.
`The structure and operation of microcontroller IC2 400
`will now be described. Microcontroller IC2 400 is prefer-
`ably a MICROCHIP brand PIC16C63, although almost any
`properly programmed microcontroller or microprocessor
`can perform the software functions described herein. The
`main function of microcontroller IC2 400 is to convert
`
`numerical data received on serial Rx pin 520 into three
`independent high frequency square waves of uniform fre-
`quency but independent duty cycles on signal output pins
`434, 454 and 474. The FIG. 2 representation of microcon-
`troller IC2 400 is partially stylized, in that persons of skill
`in the art will appreciate that certain of the twenty-eight
`standard pins have been omitted or combined for greatest
`clarity.
`Microcontroller IC2 400 is powered through pin 450,
`which is coupled to a 5 Volt source of DC power 700. Source
`700 is preferably driven from supply 300 through a coupling
`(not shown) that includes a voltage regulator (not shown).
`An exemplary voltage regulator is the LM340 3-terminal
`positive regulator, available from the National Semiconduc-
`tor Corporation, Santa Clara, Calif. The teachings of the
`LM340 datasheet are hereby incorporated by reference.
`Those of skill
`in the art will appreciate that most
`microcontrollers, and many other independently powered
`digital integrated circuits, are rated for no more than a 5 Volt
`power source. The clock frequency of microcontroller IC2
`400 is set by crystal 480, coupled through appropriate pins.
`Pin 490 is the microcontroller IC2 400 ground reference.
`Switch 600 is a twelve position dip switch that may be
`alterably and mechanically set
`to uniquely identify the
`microcontroller IC2 400. When individual ones of the
`
`twelve mechanical switches within dip switch 600 are
`closed, a path is generated from corresponding pins 650 on
`microcontroller IC2 400 to ground 690. Twelve switches
`create 212 possible settings, allowing any microcontroller
`IC2 400 to take on one of 4096 different IDs, or addresses.
`In the preferred embodiment, only nine switches are actually
`used because the DMX-512 protocol, discussed below, is
`employed.
`Once switch 600 is set, microcontroller IC2 400 “knows”
`its unique address (“who am I”), and “listens” on serial line
`520 for a data stream specifically addressed to it. A high
`speed network protocol, preferably a DMX protocol, is used
`to address network data to each individually addressed
`microcontroller IC2 400 from a central network controller
`
`(not shown). The DMX protocol is described in a United
`States Theatre Technology,
`Inc. publication entitled
`“DMX512/1990 Digital Data Transmission Standard for
`Dimmers and Controllers,” incorporated herein by refer-
`ence. Basically,
`in the network protocol used herein, a
`central controller (not shown) creates a stream of network
`data consisting of sequential data packets. Each packet first
`contains a header, which is checked for conformance to the
`standard and discarded, followed by a stream of sequential
`bytes representing data for sequentially addressed devices.
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`For instance, if the data packet is intended for light number
`fifteen, then fourteen bytes from the data stream will be
`discarded, and the device will save byte number fifteen. If as
`in the preferred embodiment, more than one byte is needed,
`then the address is considered to be a starting address, and
`more than one byte is saved and utilized. Each byte corre-
`sponds to a decimal number 0 to 255, linearly representing
`the desired intensity from Off to Full. (For simplicity, details
`of the data packets such as headers and stop bits are omitted
`from this description, and will be well appreciated by those
`of skill in the art.) This way, each of the three LED colors
`is assigned a discrete intensity value between 0 and 255.
`These respective intensity values are stored in respective
`registers within the memory of microcontroller IC2 400 (not
`shown). Once the central controller exhausts all data
`packets, it starts over in a continuous refresh cycle. The
`refresh cycle is define by the standard to be a minimum of
`1196 microseconds, and a maximum of 1 second.
`Microcontroller IC2 400 is programmed continually to
`“listen” for its data stream. When microcontroller IC2 400 is
`
`“listening,” but before it detects a data packet intended for
`it, it is running a routine designed to create the square wave
`signal outputs on pins 434, 454 and 474. The values in the
`color registers determine the duty cycle of the square wave.
`Since each register can take on a value from 0 to 255, these
`values create 256 possible different duty cycles in a linear
`range from 0% to 100%. Since the square wave frequency
`is uniform and determined by the program running in the
`microcontroller IC2 400, these different discrete duty cycles
`represent variations in the width of the square wave pulses.
`This is known as pulse width modulation (PWM).
`The PWM interrupt routine is implemented using a simple
`counter, incrementing from 0 to 255 in a cycle during each
`period of the square wave output on pins 434, 454 and 474.
`When the counter rolls over to zero, all three signals are set
`high. Once the counter equals the register value, signal
`output is changed to low. When microcontroller IC2 400
`receives new data, it freezes the counter, copies the new data
`to the working registers, compares the new register values
`with the current count and updates the output pins
`accordingly, and then restarts the counter exactly where it
`left off. Thus, intensity values may be updated in the middle
`of the PWM cycle. Freezing the counter and simultaneously
`updating the signal outputs has at least two advantages.
`First, it allows each lighting unit to quickly pulse/strobe as
`a strobe light does. Such strobing happens when the central
`controller sends network data having high intensity values
`alternately with network data having zero intensity values at
`a rapid rate.
`If one restarted the counter without
`first
`updating the signal outputs, then the human eye would be
`able to perceive the staggered deactivation of each indi-
`vidual color LED that is set at a different pulse width. This
`feature is not of concern in incandescent lights because of
`the integrating effect associated with the heating and cooling
`cycle of the illumination element. LEDs, unlike incandes-
`cent elements, activate and deactivate essentially instanta-
`neously in the present application. The second advantage is
`that one can “dim” the LEDs without the flickering that
`would otherwise occur if the counter were reset to zero. The
`
`central controller can send a continuous dimming signal
`when it creates a sequence of intensity values representing
`a uniform and proportional decrease in light intensity for
`each color LED. If one did not update the output signals
`before restarting the counter, there is a possibility that a
`single color LED will go through nearly two cycles without
`experiencing the zero current state of its duty cycle. For
`instance, assume the red register is set at 4 and the counter
`
`HTC, Exhibit 1005
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`HTC, Exhibit 1005
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`6,016,038
`
`7
`is set at 3 when it is frozen. Here, the counter is frozen just
`before the “off” part of the PWM cycle is to occur for the red
`LEDs. Now assume that the network data changes the value
`in the red register from 4 to 2 and the counter is restarted
`without deactivating the output signal. Even though the
`counter is greater than the intensity value in the red register,
`the output state is still “on”, meaning that maximum current
`is still flowing through the red LEDs. Meanwhile, the blue
`and green LEDs will probably turn off at their appropriate
`times in the PWM cycle. This would be perceived by the
`human eye as a red flicker in the course of dimming the color
`intensities. Freezing the counter and updating the output for
`the rest of the PWM cycle overcomes these disadvantages,
`ensuring the flicker does not occur.
`The network interface for microcontroller IC2 400 will
`now be described. Jacks 800 and 900 are standard RJ-8
`
`network jacks. Jack 800 is used as an input jack, and is
`shown for simplicity as having only three inputs: signal
`inputs 860, 870 and ground 850. Network data enters jack
`800 and passes through signal inputs 860 and 870. These
`signal inputs are then coupled to IC3 500, which is an
`RS-485/RS-422 differential bus repeater of the standard
`type, preferably a DS96177 from the National Semiconduc-
`tor Corporation, Santa Clara, Calif. The teachings of the
`DS96177 datasheet are hereby incorporated by reference.
`The signal inputs 860, 870 enter IC3 500 at pins 560, 570.
`The data signal is passed through from pin 510 to pin 520 on
`microcontroller IC2 400. The same data signal
`is then
`returned from pin 540 on IC2 400 to pin 530 on IC3 500.
`Jack 900 is used as an output jack and is shown for
`simplicity as having only five outputs: signal outputs 960,
`970, 980, 990 and ground 950. Outputs 960 and 970 are split
`directly from input lines 860 and 870, respectively. Outputs
`980 and 990 come directly from IC3 500 pins 580 and 590,
`respectively. It will be appreciated that the foregoing assem-
`bly enables two network nodes to be connected for receiving
`the network data. Thus, a network may be constructed as a
`daisy chain, if only single nodes are strung together, or as a
`binary tree, if two nodes are attached to the output of each
`single node.
`From the foregoing description, one can see that an
`addressable network of LED illumination or display units
`can be constructed from a collection of power modules each
`connected to a respective light module. As long as at least
`two primary color LEDs are used, any illumination or
`display color may be generated simply by preselecting the
`light intensity that each color emits. Further, each color LED
`can emit light at any of 255 different intensities, depending
`on the duty cycle of PWM square wave, with a full intensity
`pulse generated by passing maximum current through the
`LED. Further still, the maximum intensity can be conve-
`niently programmed simply by adjusting the ceiling for the
`maximum allowable current using programming resistances
`for the current regulators residing on the light module. Light
`modules of different maximum current ratings may thereby
`be conveniently interchanged.
`The foregoing embodiment may reside in any number of
`different housings. A preferred housing for an illumination
`unit is described. Turning now to FIG. 3, there is shown an
`exploded view of an illumination unit of the present inven-
`tion comprising a substantially cylindrical body section 10,
`a light module 20, a conductive sleeve 30, a power module
`40, a second conductive sleeve 50, and an enclosure plate
`60. It is to be assumed here that the light module 20 and the
`power module 40 contain the electrical structure and soft-
`ware of light module 100 and power module 200, described
`above. Screws 62, 64, 66, 68 allow the entire apparatus to be
`
`8
`mechanically connected. Body section 10, conductive
`sleeves 30 and 50 and enclosure plate 60 are preferably
`made from a material that conducts heat, most preferably
`aluminum. Body section 10 has an open end 11 a reflective
`interior portion 12 and an illumination end 13 to which
`module 20 is mechanically affixed. Light module 20 is disk
`shaped and has two sides. The illumination side (not shown)
`comprises a plurality of LEDs of different primary colors.
`The connection side holds an electrical connector male pin
`assembly 22. Both the illumination side and the connection
`side are coated with aluminum surfaces to better allow the
`
`conduction of heat outward from the plurality of LEDs to the
`body section 10. Likewise, power module 40 is disk shaped
`and has every available surface covered with aluminum for
`the same reason. Power module 40 has a connection side
`
`holding an electrical connector female pin assembly 44
`adapted to fit the pins from assembly 22. Power module 40
`has a power terminal side holding a terminal 42 for con-
`nection to a source of DC power. Any standard AC or DC
`jack may be used, as appropriate.
`Interposed between light module 20 and power module 40
`is a conductive aluminum sleeve 30, which substantially
`encloses the space between modules 20 and 40. As shown,
`a disk-shaped enclosure plate 60 and screws 62, 64, 66 and
`68 seal all of the components together, and conductive
`sleeve 50 is thus interposed between en