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`| •••••
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`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 1 of 25
`-
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`
`(12) United States Patent
`Vasylyev
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 9,678,321 B2
`Jun.13, 2017
`
`(54) LIGHT TRAPPING OPTICAL STRUCTURE
`
`(71) Applicant: Sergiy Vasylye飞 Elk Grove, CA (US)
`
`(72)
`
`Inventor: Sergiy Vas)句e飞 Elk Grove, CA (US)
`
`(73) Assignee: SVV TECHNOLOGY
`INNOVATIONS, INC., Sacramento,
`CA (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or a司justed under 35
`U.S.C. 154(b) by 0 days.
`
`(52) U.S. Cl.
`CPC ........ G02B 19/0028 (2013.01); HOlL 31/054
`(2014.12); HOlL 31/0543 (2014.12); HOlL
`31/0547 (2014.12); H02S 40/22 (2014.12);
`G02B 3/005 (2013.01); G02B 3/0056
`(2013.01); G02B 19/0004 (2013.01); H02S
`40/00 (2013.01); Y02E 10/52 (2013.01)
`(58) Field of Classification Search
`CPC ... G02B 19/0028; H02S 40/22; HOIL 31/054;
`HOIL 31/0543; HOIL 31/0547; Y02E
`10/52
`USPC .......385/刀， 36; 136/246, 259; 257厄25.009
`See application file for complete search history.
`
`(21) Appl. No.: 14/181,439
`
`(22) Filed:
`
`Feb. 14, 2014
`
`(65)
`
`US 2014/0158199 Al
`
`Prior Publication Data
`Jun. 12, 2014
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 13/572 ， 629，自led on
`Aug. 11 , 2012, now abandoned, which
`is a
`continuation of application No. 13/345,738, filed on
`Jan. 8, 2012, now Pat. No. 8,290,318, which is a
`continuation-in-part of application No. 12/764,867,
`自led on Apr. 21 , 2010, now Pat. No. 9,256,007.
`(Continued)
`
`(51)
`
`Int. Cl.
`G02B 6/34
`G02B 6/32
`HOlL 31/00
`G02B 19/00
`HOlL 31/054
`H02S 40/22
`G02B 3/00
`H02S 40/00
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2014.01)
`(2014.01)
`(2006.01)
`(2014.01)
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCU肌1ENTS
`
`6,008,449 A * 12/1999 Cole
`6,274,860 Bl
`8/2001 Rosenberg
`(Continued)
`Primary Examiner - Robert Tavlykaev
`
`136/246
`
`ABSTRACT
`(57)
`A light trapping optical cover employing an optically trans(cid:173)
`parent layer with a plurality of light def!ecting elements. The
`transparent layer is configured for an unimpeded light pas(cid:173)
`sage through its body and has a broad light input surface and
`an opposing broad light output surface. The light def!ecting
`elements def!ect light incident into the transparent layer at a
`sufliciently high bend angle with respect to a surface normal
`and direct the def!ected light toward a light harvesting
`device a司jacent to the light output surface. The def!ected
`light is retained by means of at least TIR in the system
`formed by the optical cover and the light harvesting device
`which allows for longer light propagation paths through the
`photoabsorptive layer of the device and for an improved
`light absorption. The optical cover may 臼rther employ a
`focusing array of light collectors being pairwise associated
`with the respective light def!ecting elements.
`
`19 Claims, 11 Drawing Sheets
`
`2
`y'
`
`6
`
`r圄
`
`1 甲/ - - -
`4
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 2 of 25
`
`US 9,678,321 B2
`Page 2
`
`Related U.S. Application Data
`
`(60) Provisional application No. 61/214 ，331 ，自ledonApr.
`21 , 2009, provisional application No. 61/461 ,522,
`自led on Jan. 18, 2011
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCU肌1ENTS
`
`8,354,583 B2 *
`112013 Zaban et al.
`8,402,647 B2 * 3/2013 Chui
`
`6,333 ,458 Bl
`12/2001 Forrest et al.
`6,440,769 B2
`8/2002 Peumans et al.
`7,672,549 B2
`3/2010 Ghosh et al.
`7,817,885 Bl
`10/2010 Moore et al
`8,338,693 B2 * 12/2012 Raymond ........... HOIL 3110547
`136/246
`136/246
`G02B 6/0036
`29/428
`
`2004/0103938 Al
`2008/0264483 Al
`2009/0126792 Al
`2009/0199900 Al *
`2010/0180929 Al *
`2010/0186798 Al
`2010/0278480 Al
`201110226332 Al
`2012/0012741 Al
`* cit巳d by examiner
`
`6/2004 Rider
`10/2008 Keshner et al.
`5/2009 Gruhlke et al.
`8/2009 Bita et al.
`7/2010 Raymond et al.
`7/2010 Tormen et al
`11/2010 Vasylyev
`9/2011 Ford et al.
`112012 Vasylyev
`
`136/259
`136/246
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 3 of 25
`
`u.s. Patent
`
`Jun. 13, 2017
`
`Sheet 1 of 11
`
`US 9,678,321 B2
`
`10
`
`2
`
`/
`
`8
`
`12
`FIG. 1
`
`8
`
`8
`
`8
`
`FIG 圄 3
`
`8
`
`FIG 陋 5
`
`14
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`12
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`14
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`14
`
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`
`10
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`
`F
`
`12
`
`14
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`8
`
`FIG 盟 4
`
`12
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 4 of 25
`
`u.s. Patent
`
`Jun.13, 2017
`
`Sbeet 2 of 11
`
`us 9,678,321 B2
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`14
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`

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`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 5 of 25
`
`u.s. Patent
`
`Jun. 13, 2017
`
`Sheet 3 of 11
`
`US 9,678,321 B2
`
`10
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`2
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`8
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`FIG 画 8
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`FIG.9
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`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 6 of 25
`
`u.s. Patent
`
`Jun. 13, 2017
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`Sheet 4 of 11
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`US 9,678,321 B2
`
`18
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`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 7 of 25
`
`US 9,678,321 B2
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`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 8 of 25
`
`u.s. Patent
`
`Jun. 13, 2017
`
`Sheet 6 of 11
`
`US 9,678,321 B2
`
`18
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`2
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`/
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`14
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`12
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`FIG 因 15
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`2
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`4
`
`FIG. 16
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`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 9 of 25
`
`u.s. Patent
`
`Juo.13, 2017
`
`Sheet 7 of 11
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`US 9,678,321 B2
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`l
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`iτF 呵呵呵呵 ___________________1
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`4
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`FIG 陋 18
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`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 10 of 25
`
`u.s. Patent
`
`Juo.13, 2017
`
`Sheet 8 of 11
`
`US 9,678,321 B2
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`6
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`6284
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`FIG.20
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`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 11 of 25
`
`u.s. Patent
`
`Juo.13, 2017
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`Sheet 9 of 11
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`US 9,678,321 B2
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`6
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`
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`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 12 of 25
`
`u.s. Patent
`
`Juo.13, 2017
`
`Sheet 10 of 11
`
`US 9,678,321 B2
`
`斤2
`月3'-莹
`月 11
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`60~
`
`FIG 姐 23
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`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 13 of 25
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`u.s. Patent
`
`Juo.13, 2017
`
`Sheet 11 of 11
`
`US 9,678,321 B2
`
`12
`
`FIG 圄 26A
`
`FIG 画 268
`
`FIG. 26C
`
`FIG. 26D
`
`FIG. 26E
`
`FIG 画 26F
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 14 of 25
`
`US 9,678,321 B2
`
`1
`LIGHT TRAPPING OPTICAL STRUCTURE
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`2
`allows to somewhat increase the light path length and thus
`improve absorption compared to a non-textured device, a
`significant portion of the light may still escape from the
`device without being fully absorbed. It is therefore an object
`5 of this invention to provide an improved optical structure
`This application is a continuation of application Ser. No.
`that can be used in COI可unction with light harvesting devices
`13/572 ， 629 ，自led Aug. 11, 2012, now abandoned, which is
`and that can provide efficient light trapping with minimal
`a continuation of application Ser. No. 13/345 ，738，自led Jan.
`energy loss.
`8.2012. now U.S.-Pat. No. 8.290.318. which is a continu-
`The present invention solves the above problems by
`ation-in-part of application Ser. No. 12/764，867，自led Apr. 10 providin_g a transparer:t opt~cal co;er st.~ctu:.e havi吨 oneor
`21 , 2010TMs application also claims pnodty ikom u s
`more1111crOEStructured surfaces that allow for trapping the
`provisional application Ser. No. 61/214刀 laledonApr.21 ，
`incident lightwithinthelightha飞vesting device by means of
`2009, and u.s.provisional application ser-No.61/461522at least TIR and causetlmn111ltplepassageof tlmtrapped
`filed on Jan. 18,"2011 , incorp~;ated herein by reference in its
`light y~rough. t~e activ.:_ layer thus improving the light
`15 ~bsor~tion_ an~ device effic.ie.nc!, .at the minimum consump-
`entirety.
`tion of active layer's material. Other objects and advantages
`of this invention will be apparent to those skilled in the art
`from the following disclosure.
`
`STATEMENT REGARDING FEDERALLY
`SPONSORED RESEARCH OR DEVELOP肌1ENT
`
`20
`
`BRIEF SU肌f鸟也气RY OF THE INVENTION
`
`FC
`T
`
`O 队
`卫 M
`M 刀
`
`Not Applicable
`L PA ZI
`
`n 四
`、叉口30
`
`α 叹
`C 吨
`时则
`
`OM
`E FN EO R)
`VYHC
`
`BTis NHD
`
`阻UM
`
`EV 二 YEA
`
`The present invention solves a number of light harvesting
`problems within a compact system utilizing efficient light
`deflection and trapping mechanisms. An optically transpar-
`25 ent layer is provided which can be placed on top of a light
`harvesting device and enhance the usefullight absorption in
`the device. The transparent layer employs light deflecting
`elements that communicate incident light a sufficiently high
`bend angle within the layer allowing for TIR at its light input
`30 surface and increasing the optical path length of light rays
`through the photoabsorptive layer of the light har飞咄tmg
`A portion of the material in this patent document is subjωt
`device
`to copyright protection under the copyright laws of the
`In at least one embodiment, the present invention
`United States and of other countries. The owner of the
`copyright rights has no obj 巳，ction to the facsimile reproduc-
`describes an optical cover which deflects light at a greater
`tion by anyone of the patent document or the patent disclo- 35 propagation angle with respect to a surface normal and traps
`sure, as it appears in the United States Patent and Trademark
`said light by means of a total internal reflection which allows
`Office publicly available file or records, but otherwise
`for increasing the light path length and for multiple passage
`reserves all copyright rights whatsoever. The copyright
`oflight through the photoabsorptive layer of a light harvest-
`owner does not hereby waive any of its rights to have this
`ing device.
`patent document maintained in secrecy, including without 40
`The optical cover includes a layer of optically transparent
`limitation its rights pursuant to 37 C.F.R. 91.14.
`material having a broad light input surface and an opposing
`broad light output surface extending generally parallel to the
`light input surface. The transparent layer is configured for an
`unimp巳ded transversal light passage in the direction from
`1. Field of the Invention
`45 the light input surface towards the light output surface. The
`The present invention relates to a device and method for
`transparent layer includes a plurality of light deflecting
`elements distributed along the prevailing plane of the layer
`er由ancing the light trapping in light harvesting devices.
`Particularly, the present invention relates to collecting light
`and having a cumulative aperture substantially smaller than
`from a large surface area of the light harvesting device
`the area of each ofthe broad surfaces. The light input surface
`comprising a light absorbing material and trapping the light 50 is characterized by a stepped drop in refractive index out-
`wardly from the transparent layer and by a critical angle of
`within the device so as to increase the optical path through
`the light absorbing material and improve the useful light
`TIR. Each of the light deflecting elements is configured to
`absorption. More particularly, the present invention relates
`r，巳ceive light propagating between the input and output
`to er由ancing the light trapping in photovoltaic solar panels,
`surfaces and bend the light to a greater propagation angle
`light detectors, day lighting systems, bioreactors, water 55 with respect to a normal to the light input surface. The
`light-treatment reactors, and the like.
`propagation angle of the deflωted light with respect to the
`2. Description of Background Art
`surface normal is advantageously selected to be greater than
`Many light harvesting devices employ a light-absorbing
`the TIR angle characterizing the light input surface.
`active layer that has at least a partial transparency with
`The optical cover operates in response to light receiv巳，don
`respect to the incident light or absorbs more weakly in 60 the light input surface of the optically transparent layer. At
`certain wavelengths than in the others. Conventionally, the
`least a substantial portion of light received by the apertures
`absorption in such devices can be improved by increasing
`of light deflecting elements is deflected from the original
`the thickness of the active layer. However, this results in the
`propagation path at a greater propagation angle allowing for
`increased system dimensions, material consumption, weight
`TIR 企om the light input surface. As light enters a light
`and cost. Alternati飞rely， light trapping approaches are well 65 harvesting device a司jacent to the light output surface, an
`known in which the light path is altered within the device by
`unabsorbed portion of light reflecting from the front surface
`micro-texturing one or more device surfaces. While this
`or any ofthe internallayers or surfaces ofthe light harvest-
`
`Not Applicable
`
`NOTICE OF 鸟也气TERIAL SUBJECT TO
`COPYRIGHT PROTECTION
`
`BACKGROUND OF THE INVENTION
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 15 of 25
`
`US 9,678,321 B2
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRA WING(S)
`
`4
`3
`transparent layer which increase the propagation angle with
`ing device is reflected by the light input surface by means of
`respect to a surface normal without reversing the prevailing
`TIR. This effectuates r巳'cycling of light that cannot be
`absorbed in a single pass through the photoabsorptive layer
`dir巳:ction of light propagation through the transparent layer.
`Another element of the invention is the use of light
`of the light harvesting device.
`In at least one implementation, the light deflecting ele-
`5 deflecting elements comprising a face containing both a
`refl巳:ctive and transmissive surface for redirecting the light in
`ments comprise surface relief elements. In at least one
`implementation, the light deflecting elements comprise
`relation to a normal to the prevailing plane of the transparent
`microscopic surface cavities. In at least one implementation,
`layer.
`Another element of the invention is the use of deflecting
`such cavities may have a V-shape in a cross-section.
`In altemative implementations, the light deflecting ele- 10 elements formed in either light input or light output surface
`ments comprise surface relief features that can be confìgured
`of the optically transparent layer.
`in different ways. Particularly, the surface relief features can
`Another element of the invention is the use of an array of
`be selected from the group of elements consisting of pris-
`light focusing elements which collect and focus the incident
`matic grooves, blind holes, through holes, undercuts,
`light onto the respective deflecting elements.
`notches, surface discontinuities, discontinuities in said layer, 15
`Another element of the invention is the use of an array of
`surface texture, and surface cormgations.
`deflecting and/or focusing elements which span the surface
`In at least one implementation, each ofthe light deflωting
`of the device, or a portion thereof.
`Another element of the invention is the arrangement of
`elements comprises a surface inclined at an angle with
`respect to the light input surface and configured to deflect
`the respective pairs of the light focusing elements and the
`light by means of re企action or a total internal reflection. In 20 light deflecting elements into individual opticules which can
`at least one implementation, the inclined surface has a planar
`operate independently from the other opticules.
`shape or profile. In at least one implementation, the inclined
`Another element of the invention is an optical cover
`surface has a curved shape or profile.
`configured with an attached optically responsive device
`In at least one implementation, the optical cover com-
`(e.g., photovoltaic cell or photo reactor)
`prising a plurality of light collectors distributed along the 25
`Further elements of the invention will be brought out in
`the following portions of the specification, wherein the
`prevailing plane ofthe transparent layer. The light collectors
`are preferably distributed according to the same pattem as
`detailed description is for the purpose of fully disclosing
`the plurality of light deflecting elements and pairwise form
`preferred embodiments of the invention without placing
`individual opticules with the respective light deflecting
`limitations thereon.
`elements. Each light deflecting element is disposed on the 30
`optical axis of the respective light collector and in the
`lmm巳diate proximity to the focal area ofthe collector within
`each individual opticule. In at least one implementation, the
`The invention will be more fully understood by reference
`optical cover comprises a lens array including a plurality of
`surface relief features dispos巳d in the focal plane of the 35 to the following drawings which are for illustrative purposes
`array.
`only:
`In at least one implementation, the optical cover com-
`FIG. 1 is a cross-sectional view of an optical cover
`prising a lens array where each lens of the array has a shape
`according to at least one embodiment of the present inv巳n-
`in a longitudinal section selected from the group of elements
`tion;
`consisting of elongated, cylindrical, square, rectangular and 40
`FIG. 2 is a schematic perspective view of an optical cover
`hexagonal.
`portion showing a light deflecting element shaped as an
`In at least one implementation, the optical cover com-
`elongated V-groove, according to at least one embodiment
`prises one or more optical cladding layers.
`of the present invention;
`In at least one implementation, the optical cover 如此her
`FIG. 3 shows another example of a light deflecting
`comprises one or more light harvesting devices disposed 45 element comprising a prismatic cavity, according to at least
`one embodiment of the present invention;
`along the light output surface. In at least one implementa-
`tion, the light harvesting device is selected from the group
`FIG. 4 shows a further example of a surface relief feature
`of elements consisting of one or more photovoltaic cells,
`comprising a pyramidal cavity, according to at least one
`radiation detectors, light absorbers, photo-chemical reactors
`embodiment of the present invention;
`and photo-bioreactors.
`FIG. 5 shows a yet further example of a surface relief
`In at least one implementation, the optical cover has a
`feature comprising a conical cavity, according to at least one
`form of a flexible sheet or film and can be bent to any
`embodiment of the present invention;
`suitable shape.
`FIG. 6 is a schematic perspective view of an optical cover
`卫le present invention provides a number of beneficial
`comprising a plurality of V-shape prismatic grooves in a
`elements which can be implemented either separately or in 55 cylindrical configuration, according to at least one embodi-
`ment of the present invention;
`any desired combination without departing from the present
`FIG. 7 is a schematic perspective view of an optical cover
`teachings.
`An element ofthe invention is an apparatus for collωting
`comprising a plurality of V-shape grooves in an axisym-
`metrical confìguration, according to at least one embodiment
`light over a given area and traveling in a generally trans-
`versal dir.巳ction with resp巳'ct to the light collection area.
`60 of the present invention;
`Another element of the invention is the inclusion of an
`FIG. 8 is a schematic perspective view of an optical cover
`comprising a plurality of discrete light deflecting elements
`optically transparent layer having opposing light input and
`formed by surface cavities, according to at least one embodi-
`output surfaces and configured for an unimpeded light
`passage through its body at least in a transversal direction
`ment of the present invention;
`FIG. 9 is a further example of light deflecting elements
`with respect to the either surface.
`employing another-shape cavities, according to at least one
`Another element of the invention is the inclusion of
`distributed light deflecting elemer山 within the interior of the
`embodiment of the present invention;
`
`50
`
`65
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 16 of 25
`
`US 9,678,321 B2
`
`6
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`5
`FIG. 10 is a schematic persp巳'ctive view of an optical
`cover comprising cavities or V-grooves and further employ-
`ing a lens array, according to at least one embodiment ofthe
`Referring more specifically to the drawings, for illustra-
`present invention;
`FIG. 11 is a schematic perspective view of an optical 5 tive purposes the present invention is 巳mbodied in the
`cover with a different disposition of cavities or V二grooves
`apparatus general~y shown in the preceding figures.Jt will be
`with respect to a lens array, according to at least one
`ap~r.巳ciated that the apparatus may vary as to configuration
`embodiment of thepresent invention,
`and as to details oftheparts without departing from thebasic
`FIG.12is a schematic perspective view of a rectangular
`concepts as d18closed herein Furthermore, elements repreE
`10 sented in one embodiment as taught herein are applicable
`lens array employing cylindrical (linear-focus)
`lenses,
`without limitation to other embodiments tammt herein. and
`i~'~~~bi~~~i~~';ith th~~; e;b~o~di;~~~~u a~d飞hathkiown
`according to at least one embodiment of the present inven-
`tlOn:
`in the art.
`FIG.13is a schemauc perspectiveview of a rectangular
`A wide rmgeof appl1catIonsexist for thepresent inve11-
`lens array employing 叩are-shaped poi 卧focus lens 盹 15 tion in r巳ela瓜剧H山lon川tωo t也h巳 ω le巳ω蚓讪ct叫tio川f el由ω蚓:ctron
`energy, such as light, in a broad spectrum or any suitable
`according tωoa剖t least 0αne巳 巳臼m由1由bodωlme阻巳臼nt芷t oft也h巳 pre巳s臼巳nt mv臼en-
`spectral bands or domains. Therefore, for the sake of sim-
`tlOn;
`p-licity of expression, without limiting generality of this
`FIG. 14 is a schematic perspective view of a rectangular
`lens array employing hexagon-shaped point-focus lenses,
`invention, the term "light" will be us巳d herein although the
`according to at least one embodiment of the present inven- 20 general terms "electromagnetic energy", "electromagnetic
`radiation", "radiant energy" or exemplary terms like "visible
`tion;
`light", "infrared light", or "ultraviolet light" would also be
`FIG. 15 is a schematic persp巳'ctive view of an optical
`cover illustrating an exemplary lenticular configuration
`appropriate
`employing a planar transparent layer and a lens array,
`FIG. 1 illustrates the present invention and shows a
`according to at least one embodiment of the present inven- 25 cross-s巳'ctional view of an embodiment of a light trapping
`optical cover 2. Optical cover 2 comprises a layer 8 of
`tion;
`~ssen_tially' transparen_t refractive material confined .b_e~ee~
`FIG. 16 is a schematic cross-s巳:ctional view of an optical
`cover illustrating its operation in coIUunction with a light
`broad surface 10and m opposing broad surface12Both
`harvesting deVIce, accordmg to at least oneembodment of
`surfaces11and12arebroadlyextendmg both longitudinally
`tlm present Inv en t ion -30 and laterally so that thethickness of traIBparent layer 8is
`FIG. 17 is a scl…剖lC Vle矶 in a cross-section, and 町 substan削ly smaller ∞mpared to its other two dimensions
`Both surfaces 10 and 12 are also essentially smooth and
`tracing of a light harvesting system employing an optical
`transparent and are configured for a good optical transmis(cid:173)
`cover, according to at least one embodiment of the present
`sion in either direction. Layer 8 is configured for a generally
`35 unimp巳ded light passage through its body in either direction.
`mventlOn;
`FIG. 18 is，~ ,schematic view, in a cross-section, and .ra~
`Parti~ularly， lay~r 8 should allow for ~n unimpeded light
`tracing of a light harvesting system e~ploy!ng an opt.i.cal
`passage of light through any parts of the l~yer in the
`trans;ersal di;ection. L;yer 8 SîlOUld also be ~ufficiently
`cover in an altemative exemplary configuration, according
`transparent and allow ligÍlt to travel considerable distances
`to at least one embodiment of the present invention;
`FIG. 19 is a schematic view, in a cross-section, and ray 40 within the layer along the layer's prevailing plane.
`Optical cover 2 is generally designed to be laid flat on top
`tracing of a sunlight harvesting system employing an optical
`cover and photovoltaic devi邸， according to at least one
`of a light h盯创ting device (not shown in FIG. 1) where
`embodiment of the present invention;
`either one of surfaces 10 and 12 can be designated to be a
`FIG. 20 is another example and raytracing of a sunlight
`light input surface facing the light source while the other
`harvesting system employing an optical cover and photo- 45 surface can be designated to be a light output surface facing
`the light harvesting device. In operation, cover 2 and the
`voltaic devices, according to at least one embodiment ofthe
`underlying light harvesting device may be positioned with
`present invention;
`FIG. 21 is a further example and raytracing of a sunlight
`their prevailing surface planes perpendicular to the light
`source direction. However, they may also be designed to
`harvesting system employing an optical cover and liquid-
`carrying photo reactor, according to at least one embodiment 50 operate at any angle other than normal.
`of the present invention;
`The refractive material of layer 8 should be high enough
`FIG. 22 is a schematic view, in a cross-section, and ray
`so that when optical cover 2 is coupled to a light harvesting
`device, the light input surface of layer 8 can form an optical
`tracing of a an optical cover showing microstructures asso-
`ciated with a lens arr町， according to at least one embodi-
`interface characterized by a stepped drop in refractive index
`55 outwardly from said layer. It will be appr巳'CÏated by those
`ment of the present invention;
`FIG. 23 is a schematic cross-sectional view showing an
`skilled in the art of optics that when referring to light or other
`exemplary individual light deflecting element and raytrac-
`waves passing through a boundary formed between 阳O
`ing, according to at least one embodiment of the present
`different refractive m巳dia， such as air and glass, the ratio of
`invention;
`the sines of the angles of incidence and of refraction is a
`FIG. 24 is a schematic view, in a cross-section, illustrating 60 constant that depends on the ratio of refractive indices ofthe
`a step in making an optical cover, according to at least one
`media. Referring to the refractive medium oflayer 8 and the
`embodiment of the present invention;
`outside medium immediately a司jacent to the light input
`surface, it will be appreciated that the following relationship
`FIG. 25 is a schematic view of an optical cover in a sh臼t
`roll form, according to at least one embodiment of the
`can describe light bending properties ofthe optical interface
`65 formed by the light input surface: n1 sin 中 1二n2 sin 仇， where
`present invention;
`FIG. 26A through FIG. 26F illustrate various cross-
`n1 and n2 are the refractive indices ofthe material oflayer 8
`and the outside medium, respectively, and 中 1 and 中2 are the
`sections of light deflecting elements.
`
`

`

`Case 6:20-cv-00139-ADA Document 1-4 Filed 02/21/20 Page 17 of 25
`
`US 9,678,321 B2
`
`•
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`•
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`8
`7
`gation through cover 2 will be the dir巳'ction from surface 12
`respective propagation angles that light makes in respωt to
`the surface normal. It will be further appreciated that, in
`to surface 10 along a surface normal. It will be appreciated
`that, when surfaces 10 and 12 are parallel to each other, a
`respect to the light internally striking the light input surface
`from layer 8, the s缸丑e optical interface can also be charac-
`normal to one of the surfaces will also be a normal to the
`terized by the angle of a Total Internal Ref!ection (TIR) 5 other surface and to the prevailing plane oflayer 8 and cover
`2. It will further be appreciated that, in accordance with the
`which is the value of 中2 forwhich 中 1 equals 900
`• A TIR angle
`above definitions, propagation angle 中D may take values
`中 TIR can be found from the following expression:
`中刀R二arcsin(n2/n1 'sin 90 0)二arcsin(n2/n1 ). In an exemplary
`from 0 0 to 1800
`case of the interface between glass with the ref!ective index
`According to a preferred embodiment of the present
`n 1 of about 1.51 and air with 1马 of about 1 ，中TIR is approxi- 10 invention, light def!ecting elements 14 are designed to result
`mately equal to 41 .47 0
`in the propagation angle 中'D being greater than TIR angle
`Layer 8 comprises a plurality of light def!ecting elements
`中TIR at the optical interface formed by the light input surface
`14 within the boundaries formed by surfaces 10 and 12.
`of layer 8 and less than 90 0
`• This ensures that the light
`Light def!ecting elements 14 are spaced apart from each
`def!ection by elements 14 will not prevent light from reach-
`other and distribut巳，d along the prevailing plane of cover 2. 15 ing the light output surface yet providing for a substantial
`Each light def!ecting element 14 has a substantially smaller
`light deviation from the original propagation path and
`aperture than the light receiving aperture of optical cover 2.
`enabling TIR at the light input surface of layer 8. By using
`the above notations for the refractive indices, a preferred
`Furtherr丑ore， the aperture of each light def!ecting element 14
`propagation angle 中D of light def!ected by light def!ecting
`is preferably smaller than the a司jacent spacing area so that
`the plurality of light def!ecting elements 14 cumulatively 20 elements 14 may thus be express巳d by the following rela-
`occupies a sufliciently small area compared to either sur-
`tionship: arcsin (n2/n1 )<中D<90 0 •
`In FIG. 1, light def!ecting elements 14 are exemplifi巳d by
`faces 10 and 12.
`According to an aspect of the present invention, it is
`high aspect ratio prismatic cavities formed in broad surface
`preferred that each light def!ecting element 14 is configured
`10. Each of the high aspect ratio prismatic cavities may be
`to communicate a generally greater bend angle to li冉 25 characterized by 阳o generally planar and symmetrically
`propagating between surfaces 10 and 12 compared to the
`disposed faces located between surfaces 10 and 12 and
`case when light passes through layer 8 simply by crossing
`inclined at an angle with respect to both surfaces. In at least
`some embodiments of the present invention and in the
`surfaces 10 and 12 and without striking any light def!ωting
`element 14. Each light def!ecting element 14 should preιcontext of describing a surface microstructure element, such
`erably be configured to alter the ordinary light path between 30 as, for example, a surface cavity having a prismatic or
`conical shape, the term "high aspect ratio" is meant to mean
`surface 10 and 12 yet providing for an unimpeded passage
`a geometric configuration of the microstructure element, in
`of incident light through layer 8.
`By way of example and not limitation, light def!ωting
`a cross-s巳'ction， where the height or depth ofthe microstruc-
`elements 14 may be configured to receive light incident onto
`ture element is approximately equal or greater than its base
`the light input surface of layer 8 at normal angles (which 35 at the surface. This term also includes the case when the
`corresponds to zero incidence angles with respect to a
`height of the microstructure element is much greater than the
`surface normal) and def!ect it at an angle greater than TIR
`base thus corresponding to a deep drawn cavity or a hole
`angle <ÞTIR with respect to the surface normal. In a further
`with almost vertical walls.
`non-limiting example, each li悼t def!巳'cting element 14 may
`According to an embodiment of the present invention
`be configured to receive a fan of rays having a predefined 40 illustrated in FIG. 1, an individuallight def!ecting elements
`angular spread and def!ect each ray from the original propa-
`14 can be viewed as any suitable localized interruption or
`gation path so that at least a substantial part of def!ected light
`alteration of the otherwise smooth surface 10 that alters the
`rays continues prop