Source: http://www.google.com/patents/US8188687?dq=5631832
Timestamp: 2015-05-23 06:19:21
Document Index: 419381014

Matched Legal Cases: ['Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 201010113979']

Patent US8188687 - Light emitting device for AC power operation - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsDisclosed is an improved light-emitting device for an AC power operation. A conventional light emitting device employs an AC light-emitting diode having arrays of light emitting cells connected in reverse parallel. The arrays in the prior art alternately repeat on/off in response to a phase change of...http://www.google.com/patents/US8188687?utm_source=gb-gplus-sharePatent US8188687 - Light emitting device for AC power operationAdvanced Patent SearchPublication numberUS8188687 B2Publication typeGrantApplication numberUS 11/994,308PCT numberPCT/KR2006/001726Publication dateMay 29, 2012Filing dateMay 9, 2006Priority dateJun 28, 2005Also published asCN101672436A, CN101672436B, CN101795510A, CN101799126A, CN101799126B, CN101846249A, CN101846249B, CN101865375A, CN101865375B, CN101865438A, CN101865438B, EP1905102A1, EP1905102A4, EP2367400A2, EP2367400A3, EP2384088A2, EP2384088A3, EP2384088B1, EP2536255A1, EP2536255B1, US8395332, US8716946, US8860331, US8866417, US20080211421, US20100277084, US20110031891, US20120217885, US20130169174, US20140028204, WO2007001116A1Publication number11994308, 994308, PCT/2006/1726, PCT/KR/2006/001726, PCT/KR/2006/01726, PCT/KR/6/001726, PCT/KR/6/01726, PCT/KR2006/001726, PCT/KR2006/01726, PCT/KR2006001726, PCT/KR200601726, PCT/KR6/001726, PCT/KR6/01726, PCT/KR6001726, PCT/KR601726, US 8188687 B2, US 8188687B2, US-B2-8188687, US8188687 B2, US8188687B2InventorsChung Hoon Lee, James S. Speck, Hong San Kim, Jae Jo Kim, Sung Han Kim, Jae Ho LeeOriginal AssigneeSeoul Opto Device Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (31), Non-Patent Citations (6), Referenced by (14), Classifications (16), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetLight emitting device for AC power operation
US 8188687 B2Abstract
Disclosed is an improved light-emitting device for an AC power operation. A conventional light emitting device employs an AC light-emitting diode having arrays of light emitting cells connected in reverse parallel. The arrays in the prior art alternately repeat on/off in response to a phase change of an AC power source, resulting in short light emission time during a � cycle and the occurrence of a flicker effect. An AC light-emitting device according to the present invention employs a variety of means by which light emission time is prolonged during a � cycle in response to a phase change of an AC power source and a flicker effect can be reduced. For example, the means may be switching blocks respectively connected to nodes between the light emitting cells, switching blocks connected to a plurality of arrays, or a delay phosphor. Further, there is provided an AC light-emitting device, wherein a plurality of arrays having the different numbers of light emitting cells are employed to increase light emission time and to reduce a flicker effect.
a light emitting diode (LED) chip comprising a substrate, an array of light emitting cells connected in series on the substrate, another array of light emitting cells connected in series on the substrate, the other array being connected in reverse parallel to the array of the light emitting cells, a source terminal, and a ground terminal; and
switching blocks that are each electrically connected to the source terminal, the ground terminal, and a respective one of a plurality of nodes between each of the light emitting cells, to sequentially turn on and off the light emitting cells, when an AC voltage is applied to the array,
wherein an n-th switching block (n being a positive integer) shorts the ground terminal and a node to which the n-th switching block is connected, when a voltage difference (Vac) between the source and ground terminals is in a range of (Predetermined Voltage�n) to (Predetermined Voltage�(n+1)), and opens the node from the ground terminal if the voltage difference (Vac) is greater than (Predetermined Voltage�(n+1)), and
wherein nodes between the light emitting cells of the other array of light emitting cells are respectively connected to the switching blocks.
2. The light emitting device as claimed in claim 1, wherein the predetermined voltage is a forward voltage of the light emitting cells at a reference current.
3. The light emitting device as claimed in claim 2, wherein the value of the reference current is 15 to 25 mA.
4. The light emitting device as claimed in claim 1, wherein the light emitting cells are turned off in an order reverse to the order in which the light emitting cells are turned on.
5. A light-emitting device for an AC power operation, the device comprising a light emitting diode chip comprising:
first arrays positioned on the substrate, the first arrays each having a different number of light emitting cells that are all connected to one another in series, the first arrays being connected in parallel to one another;
second arrays positioned on the substrate, the second arrays each having a different numbers of light emitting cells that are all connected to one another in series, the light emitting cells of the second arrays being connected in reverse parallel to the light emitting cells of the first arrays; and
a switching block connected to end portions of each of the arrays and directly connected an AC power source, to individually and sequentially operate to each of the first arrays and the second arrays, depending on a voltage level of the AC power source, such that when one of the arrays is turned on, the other arrays are electrically bypassed by the switching block.
6. The light-emitting device for an AC power operation as claimed in claim 5, wherein one terminal of each of the first and second arrays is connected in common to a first power source connection terminal, and the other terminals thereof are connected to second power source connection terminals, respectively.
7. The light-emitting device for an AC power operation as claimed in claim 5, wherein corresponding ones of the first and second arrays have the same number of light emitting cells.
8. The light-emitting device for an AC power operation as claimed in claim 7, wherein an array having the greater number of the light emitting cells in the first and second arrays has larger light emitting cells.
9. The light-emitting device for an AC power operation as claimed in claim 5, further comprising a common resistor serially connected in common to the first and second arrays.
10. The light-emitting device for an AC power operation as claimed in claim 5, wherein in each of the first and second arrays, light emitting cells within an array having the smallest number of the light emitting cells have luminous intensity larger than that of light emitting cells within an array having the greatest number of the light emitting cells.
11. The light-emitting device for an AC power operation as claimed in claim 10, wherein the light emitting cells within the array having the smallest number of the light emitting cells have roughened surfaces so that they can have luminous intensity larger than that of the light emitting cells within the array having the greatest number of the light emitting cells.
12. The light-emitting device for an AC power operation as claimed in claim 10, wherein the light emitting cells within the array having the smallest number of the light emitting cells have inclined side surfaces so that they can have luminous intensity larger than that of the light emitting cells within the array having the greatest number of the light emitting cells.
a plurality of light emitting diode (LED) chips, each LED chip comprising:
an array of light emitting cells connected in series through metal wires on the substrate, each light emitting cell comprising a first conductive type semiconductor layer, a second conductive type semiconductor layer and an active layer interposed between the first conductive type semiconductor layer and the second conductive type layer, the light emitting cells being isolated from each other, and
an electrode formed on the second conductive type semiconductor layer, the electrode being a transparent electrode through which light is transmittable,
wherein the substrate has a partial region exposed by removing the second conductive type semiconductor layer, the active layer and the first conductive type semiconductor layer;
switching blocks that are each electrically connected to the source terminal, the ground terminal, and a respective one of a plurality of nodes between the LED chips, to sequentially turn on and off the LED chips, when an AC voltage is applied to the array,
wherein nodes between the LED chips are respectively connected to the switching blocks.
This application is a U.S. national phase application of PCT International Application No. PCT/KR2006/001726, filed May 9, 2006, which claims priority of Korean Patent Application No. 10-2005-0056175 filed Jun. 28, 2005, Korean Patent Application No. 10-2005-0104952 filed Nov. 3, 2005, Korean Patent Application No. 10-2005-0126872 filed Dec. 21, 2005, Korean Patent Application No. 10-2005-0126873 filed Dec. 21, 2005, Korean Patent Application No. 10-2005-0126904 filed Dec. 21, 2005, and Korean Patent Application No. 10-2006-0013322 filed Feb. 11, 2006, the contents of which are incorporated herein by reference in their entirety.
The light emitting cells C1 to Cn of the array are operated for a � cycle of the AC voltage power source and the other array connected in reverse parallel to the array is operated for the other � cycle thereof. Accordingly, the arrays are alternately operated by means of the AC voltage power source.
The switching blocks may be connected to source and ground terminals of the array. At this time, an n-th switching block may short the ground terminal and a node to which the n-th switching block is connected when a voltage difference Vac between the source and ground terminals is in a range of (Predetermined Voltage�n) to (Predetermined Voltage�(n+1)), and may open the node from the ground terminal if the voltage difference Vac is greater than (Predetermined Voltage�(n+1)). Accordingly, when an AC voltage is increased, the switching blocks sequentially repeat the short-circuiting and the opening so that the light emitting cells can be sequentially turned on. When the AC voltage is decreased, the light emitting cells are sequentially turned off.
The light emitting cells with the roughened surfaces may constitute arrays of which the number is � of the number of the arrays in each of the first and second arrays. In this case, the arrays of the light emitting cells with the roughened surfaces have the relatively smaller number of the light emitting cells. Meanwhile, the arrays of the light emitting cells with the roughened surfaces may be limited to arrays having the smallest number of the light emitting cells in each of the first and second arrays.
The light emitting cells with the inclined side surfaces may constitute arrays of which the number is � of the number of the arrays in each of the first and second arrays. In this case, the arrays of the light emitting cells with the inclined side surfaces are have the relatively smaller number of the light emitting cells. Meanwhile, the arrays of the light emitting cells with the inclined side surfaces may be limited to arrays having the smallest number of the light emitting cells in each of the first and second arrays.
The light emitting cells C1 to Cn are connected in series, and nodes L1 to Lnn-1 are positioned between light emitting cells. Switching blocks G1 to Gn-1 are connected to the nodes L1 to Ln-1, respectively. That is, the switching block G1 is connected to the node L1 between the light emitting cells C1 and C2, and the switching block G2 is connected to the node L2 between the light emitting cells C2 and C3. The switching block Gn-1 is connected to the node Ln-1 between the light emitting cells C1 and Cn in such a manner.
When a voltage Vac of the source terminal S is within a range of (Predetermined Voltage�n) to (Predetermined Voltage�(n+1)), each of the switching blocks Gn shorts the node Ln and the ground terminal G. Here, n denotes an ordinal number for a switching block. In this case, the switching blocks G1 to Gn-1 bypass a current to the ground terminal G. Meanwhile, if the voltage Vac of the source terminal S is (Predetermined Voltage�(n+1)) or more, each of the switching blocks Gn opens the node Ln from the ground terminal G. In this case, the currents that are bypassed through the switching blocks G1 to Gn-1 are cut off. Further, if the voltage Vac of the source terminal S is smaller than (Predetermined Voltage�n), each of the switching blocks G1 to Gn-1 opens the node Ln from the ground terminal G.
As the AC voltage Vac is increased, the processes in which the switching blocks G1 to Gn-1 are shorted and subsequently opened are repeated, so that the switching blocks G1 to Gn-1 are sequentially opened, and thus, the light emitting cells C1 to Cn are sequentially turned on.
Table 1 below summarizes the turn-on and turn-off operations of the light emitting cells with time for a � cycle.
Cn−1 Cn 0
Meanwhile, at least two arrays of light emitting cells connected in series may be connected in reverse parallel to each other and switching blocks may be connected to nodes between the light emitting cells of each of the arrays, respectively. Meanwhile, the switching blocks may be connected in common to the respective arrays. Accordingly, the switching blocks can allow the light emitting cells within one array to be sequentially turned on or off during a � cycle and then allow the light emitting cells within another array to be sequentially turned on and off during a latter � cycle.
Light emitting cells each of which has the second conductive type semiconductor layer 29 a with the roughened surface may construct the arrays in the first and sixth embodiments of the present invention, which have been previously described above. Further, in the first and sixth embodiments, arrays of which the number is � or less of the number of entire arrays may be constructed of the light emitting cells having the second conductive type semiconductor layers 29 a with the roughened surfaces. For example, arrays of which the number is � or less of the number of the first arrays and arrays of which the number is � or less of the number of the second arrays in FIGS. 14 and 15 may be constructed of the light emitting cells having the second conductive type semiconductor layers 29 a with the roughened surfaces; and arrays of which the number is � or less of the number of the arrays in FIG. 16 may be constructed of the light emitting cells having the second conductive type semiconductor layers 29 a with the roughened surfaces. At this time, the light emitting cells having the second conductive type semiconductor layers 29 a with the roughened surfaces constitute arrays having the smaller number of the light emitting cells, and arrays having the greater number of the light emitting cells are constructed of light emitting cells having flat surfaces.
Referring to FIG. 18, light emitting cells in this embodiment are substantially identical with those described with reference to FIG. 5, and light emitting cell arrays may be arranged in the same manner as described in the first to sixth embodiments. However, in this embodiment, each of the light emitting cells is formed to have inclined side surfaces. The light emitting cells each of which has the inclined side surfaces constitute the arrays (A1 and RA1 in FIGS. 14 to 17) that are initially turned on in the same manner as the light emitting cells having the roughened surfaces, and may constitute arrays of which the number is � of the number of the first and second arrays in FIGS. 14 to 17.
The delay phosphor may be a silicate, an aluminate, a sulfide phosphor or the like disclosed in U.S. Pat. Nos. 5,770,111, 5,839,718, 5,885,483, 6,093,346, 6,267,911 and the like. For example, the delay phosphor may be (Zn, Cd)S:Cu, SrAl2O4:Eu, Dy, (Ca,Sr)S:Bi, ZnSiO4:Eu, (SrZn,Eu,Pb,Dy)O.(Al,Bi)2O3, m(Sr,Ba)O.n(Mg,M)O.2(Si,Ge)O2:Eu, Ln (wherein, 1.5≦m≦3.5; 0.5≦n≦1.5; M is at least one element selected from the group consisting of Be, Zn and Cd; and Ln is at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Th, Dy, Ho, Er, Tm, Yb, Klu, B, Al, Ga, In, Tl, Sb, Bi, As, P, Sn, Pb, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Cr and Mn), or the like.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4271408 *Oct 12, 1979Jun 2, 1981Stanley Electric Co., Ltd.Colored-light emitting displayUS4298869 *Jun 25, 1979Nov 3, 1981Zaidan Hojin Handotai Kenkyu ShinkokaiLight-emitting diode displayUS5770111Apr 12, 1996Jun 23, 1998Kabushiki Kaisha Tokyo Kagaku KenkyushoPhosphor with afterglow characteristicUS5839718Jul 22, 1997Nov 24, 1998Usr Optonix Inc.Long persistent phosphorescence phosphorUS5885483Aug 29, 1996Mar 23, 1999Hao; QinglongLong afterglow phosphor and a process for the preparing thereofUS6093346Dec 24, 1997Jul 25, 2000Xiao; ZhiguoLong afterglow silicate luminescent material and its manufacturing methodUS6252254Nov 30, 1998Jun 26, 2001General Electric CompanyLight emitting device with phosphor compositionUS6267911Nov 6, 1998Jul 31, 2001University Of Georgia Research Foundation, Inc.Phosphors with long-persistent green phosphorescenceUS6600175 *Mar 26, 1996Jul 29, 2003Advanced Technology Materials, Inc.Solid state white light emitter and display using sameUS6641294 *Mar 22, 2002Nov 4, 2003Emteq, Inc.Vehicle lighting assembly with stepped dimmingUS7081722 *Feb 4, 2005Jul 25, 2006Kimlong HuynhLight emitting diode multiphase driver circuit and methodUS7195381Jan 22, 2002Mar 27, 2007Donnelly CorporationVehicle interior LED lighting systemUS20010033503Mar 9, 2001Oct 25, 2001Hamp Charles HenryLow power lighting system with LED illuminationUS20020145384Jun 15, 2001Oct 10, 2002Balu JeganathanLed lampUS20040075399Oct 22, 2002Apr 22, 2004Hall David CharlesLED light engine for AC operation and methods of fabricating sameUS20040124422Oct 1, 2003Jul 1, 2004Takahiko SakamotoLight-emitting diodeUS20040195576 *Mar 12, 2004Oct 7, 2004Toshihiko WatanabeLight-emitting device, light-emitting apparatus, image display apparatus, method of manufacturing light-emitting device, and method of manufacturing image display apparatusUS20070273299 *Feb 25, 2005Nov 29, 2007Michael MiskinAC light emitting diode and AC LED drive methods and apparatusUS20090167192 *Jun 27, 2005Jul 2, 2009Koninklijke Philips Electronics, N.V.Active frame system for ambient lighting using a video display as a signal sourceCN1289456ANov 30, 1999Mar 28, 2001通用电气公司Light emitting device with phosphor compositionCN1349261AOct 13, 2000May 15, 2002国联光电科技股份有限公司Glass gluing process of producing high-brightness luminoud dipoleCN1460294AJun 15, 2001Dec 3, 2003塞斯特马科斯股份有限公司Led灯DE3832109A1Sep 21, 1988Mar 22, 1990Juergen MunzLuminaireEP0967590A1Jun 25, 1998Dec 29, 1999Hewlett-Packard CompanyOptical display device using LEDs and its operating methodEP1318701A2Nov 22, 2002Jun 11, 2003Audi AgApparatus and method for driving a plurality of LedsJP2000068555A Title not availableJP2001156331A Title not availableKR20040032360A Title not availableWO2000033390A1Nov 30, 1999Jun 8, 2000Gen ElectricLight emitting device with phosphor compositionWO2001097287A1Jun 15, 2001Dec 20, 2001Systemax Pty LtdLed lampWO2004023568A1Aug 28, 2003Mar 18, 2004Shiro SakaiLight-emitting device having light-emitting elements* Cited by examinerNon-Patent CitationsReference1Chinese Office Action for CN Patent Application No. 201010113979.5 issued on Apr. 25, 2011.2Extended European Search Report of EP 06757670.2 dated on May 10, 2010.3Final Office Action dated Dec. 27, 2011 for U.S. Appl. No. 12/908,692.4Final Office Action of U.S. Appl. No. 12/837,805 mailed on Aug. 18, 2011.5Non-Final Office Action of U.S. Appl. No. 12/908,692 issued on Jul. 13, 2011.6U.S. Non-Final Office Action dated Feb. 4, 2011 (from co-pending U.S. Appl. No. 12/837,805).Referenced byCiting PatentFiling datePublication dateApplicantTitleUS8373363 *May 24, 2010Feb 12, 2013Once Innovations, Inc.Reduction of harmonic distortion for LED loadsUS8465167Sep 16, 2011Jun 18, 2013Lighting Science Group CorporationColor conversion occlusion and associated methodsUS8519635 *Nov 30, 2010Aug 27, 2013Aussmak Optoelectronics Corp.Light-emitting deviceUS8545034Jan 24, 2012Oct 1, 2013Lighting Science Group CorporationDual characteristic color conversion enclosure and associated methodsUS8643308Jun 27, 2010Feb 4, 2014Once Innovations, Inc.Spectral shift control for dimmable AC LED lightingUS8702259May 9, 2013Apr 22, 2014Lighting Science Group CorporationColor conversion occlusion and associated methodsUS8730558Oct 3, 2012May 20, 2014Lighting Science Group CorporationWavelength converting lighting device and associated methodsUS8796955 *Oct 29, 2012Aug 5, 2014Once Innovations, Inc.Reduction of harmonic distortion for LED loadsUS20110127919 *Nov 30, 2010Jun 2, 2011Aussmak Optoelectronics Corp.Light-emitting deviceUS20110273098 *May 24, 2010Nov 10, 2011Once Innovations, Inc.Reduction of Harmonic Distortion for LED LoadsUS20120229038 *Mar 12, 2012Sep 13, 2012Intematix CorporationMillisecond decay phosphors for ac led lighting applicationsUS20130187556 *Jan 24, 2013Jul 25, 2013Intemetix CorporationLong Decay Phosphors for Lighting ApplicationsUS20130207556 *Oct 29, 2012Aug 15, 2013Once Innovations, Inc.Reduction of Harmonic Distortion for LED LoadsUS20140111091 *Dec 30, 2013Apr 24, 2014Zdenko GrajcarSpectral shift control for dimmable ac led lighting* Cited by examinerClassifications U.S. Classification315/323, 315/209.00R, 315/312International ClassificationH01L33/50, H01L33/32, H05B37/00, H01L33/06Cooperative ClassificationH05B33/0821, H05B33/0806, H05B33/0824, H01L27/153, H01L27/156, H05B33/02, H05B33/083European ClassificationH05B33/08D1L2, H05B33/08D1Legal EventsDateCodeEventDescriptionApr 21, 2014ASAssignmentOwner name: SEOUL VIOSYS CO., LTD, KOREA, REPUBLIC OFFree format text: CHANGE OF NAME;ASSIGNOR:SEOUL OPTO DEVICE CO., LTD;REEL/FRAME:032723/0126Effective date: 20130711Jan 25, 2008ASAssignmentOwner name: SEOUL OPTO DEVICE CO., LTD., KOREA, REPUBLIC OFFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LEE, CHUNG HOON;SPECK, JAMES S.;KIM, HONG SAN;AND OTHERS;REEL/FRAME:020419/0456Effective date: 20071228RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services