THAI MATAA MICANAL DO THAT MAN HAR MITTE

US009971162B2

(12) United States Patent

Banerjee et al.
(10) Patent No.: US 9 ,971, 162 B2
(45) Date of Patent: May 15 , 2018
(54 ) APPARATUSES AND METHODS FOR (58 ) Field of Classification Search
MAKING AN OBJECT APPEAR CPC ...... GO2B 5 /30 ; G02B 5 /3025 ; GO2B 5 /3083 ;
TRANSPARENT GO2B 21 / 14 ; GO2B 27 /024 ;
(71) Applicant: Toyota Motor Engineering & (Continued )
Manufacturing North America, Inc., (56 ) References Cited
Erlanger, KY (US) U .S. PATENT DOCUMENTS
(72 ) Inventors : Debasish Banerjee , Ann Arbor, MI 4 ,684 ,255 A * 8/ 1987 Ford ........ G01J 3 /453
(US ); Hideo Iizuka, Nissin (JP ) 356 / 455
(73 ) Assignee: Toyota Motor Engineering & 5, 941,596 A 8/ 1999 See
Manufacturing North America , Inc., (Continued )
Plano , TX (US ) OTHER PUBLICATIONS
( * ) Notice: Subject to any disclaimer, the term of this Hongsheng Chen et al., “ Broadband polygonal invisibility cloak for
patent is extended or adjusted under 35 visible light” , Scientific Reports, Feb . 9 , 2012 , pp . 1 - 14 .
U . S .C . 154 (b ) by 74 days. (Continued )
(21) Appl. No.: 15 / 185 , 988 Primary Examiner — Loha Ben
(22) Filed : Jun . 17, 2016 (74 ) Attorney, Agent, or Firm — Dinsmore & Shohl LLP
(65 ) Prior Publication Data (57) ABSTRACT
A cloaking device includes cloaking region boundary planes
US 2017 /0227781 A1 Aug . 10 , 2017 oriented non - planar to each other, each of the cloaking
region boundary planes having an outward facing mirror
Related U .S . Application Data surface and an inward facing opaque surface. The cloaking
(60 ) 5Provisional application No. 62/291,920, filed on Feb . device includes a cloaking region bounded at least partially
, 2016 . by the inward facing opaque surfaces of the cloaking region
boundary planes . Half mirrors are spaced apart from and
(51) Int. Ci. generally parallel to the outward facing mirror surfaces such
G02B 27 / 14 ( 2006 .01) that a half mirror is spaced apart from and generally parallel
GO2B 27/ 10 ( 2006 .01) to each outward facing mirror surface . Light from an object
(Continued ) on an object- side of the cloaking device is directed around
an article within the cloaking region and forms an image on
(52) CPC
U .S. CI
.
. GO2B 27 / 14 (2013 . 01 ); B60R 13 /025 an image -side of the cloaking device such the article appears
transparent to an observer looking towards the object.
(2013.01); GO2B 5 /3083 (2013 .01);
(Continued ) 20 Claims, 9 Drawing Sheets

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 US 9,971, 162 B2
Page 2
(51) Int. Ci. (56 ) References Cited
GO2B 27/28 ( 2006 .01) U . S . PATENT DOCUMENTS
GO2B 5 /30 (2006 .01)
B60R 13 /02 ( 2006 .01) 5,982,343 A * 11/ 1999 Iba .................... GO2B 27 /345
0172/ 8
B60R 1 /08 ( 2006 .01)
(52 ) U .S. CI. 6 ,130,784 A * 10/2000 Takahashi .......... HO4N 5/7491
348 / E5 . 145
CPC ....... G02B 27/ 1086 (2013 .01); G02B 27 /283 2015 /0248013 AL 9 /2015 Chen et al.
( 2013 . 01) ; B6OR 1 /082 (2013 .01) ; B6OR
2013/ 0287 ( 2013 .01); GO2B 5 / 30 ( 2013 .01) ; OTHER PUBLICATIONS
G02B 5/ 3025 (2013.01); G02B 27/ 144
(2013 .01) John C . Howell et al., “ Simple , broadband , optical spatial cloaking
(58 ) Field of Classification Search of very large objects" , Department of Physics and Astronomy,
CPC .. GO2B 27 / 1086 ; GO2B 27 / 14 ; G02B 27 / 141; University of Rochester, www .physics.optics, arXiv: 1306 .0863
GO2B 27 / 143 ; GO2B 27 / 144 ; B6OR 1 /08 ; < /abs/ 1306 . 0863 > [physics .optics], Jun . 2013.
B6OR 1 /082; B6OR 13 /02, B6OR 13 /025 ; Yihao Yang et al., “ Towards omnidirectional, large scale , full
B6OR 2013 /0287; GO3B 21 / 2066 ; GOBB polarization , and broadband practical invisibility cloaks : challenges
21/2073 and progress ” , EPJ Appl. Metamat. 2014 , 1 , 7 .
USPC .............. 359 /299 – 304, 493 , 618 , 629 , 634 ; “ Physics demonstrations: cloaking device ?” , Apr. 25 , 2013 ; URL :
https://skullsinthestars.com /2013 /04/25/ physics -demonstrations
396 /331, 386 , 544 ; 353 /12 , 14 , 20 , 28 , cloaking - device .
353/66
See application file for complete search history. * cited by examiner
U . S . Patent _ May 15, 2018 Sheet10f9 US 9, 971 , 162 B2

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 US 9 ,971, 162 B2
APPARATUSES AND METHODS FOR positioned within the CR is redirected around the CR , and
MAKING AN OBJECT APPEAR forms an image of the object on the image - side of the
TRANSPARENT cloaking assembly such that the vehicle article appears
transparent to an observer looking in a direction towards the
RELATED APPLICATION 5 object.
In embodiments , the cloaking assembly has four CR
This application claims the benefit of U . S . Provisional boundary planes and four half mirrors. The four CR bound
Patent Application Ser. No . 62/ 291 , 920 filed Feb . 5 , 2016 , ary planes are oriented generally orthogonal to each other,
the entirety of which is incorporated herein by reference . the CR is bounded by the four CR boundary planes, and each
of the half mirrors are spaced apart and generally parallel to
TECHNICAL FIELD one of the outward facing mirror surfaces such that a half
mirror is spaced apart and generally parallel to each outward
The present specification generally relates to apparatuses facing mirror surface . Each of the half mirrors may be
and methods for making an object appear transparent and , selected from a p - polarization half mirror or an s -polariza
more
m specifically , to cloaking devices for pillars of vehicles 15
and methods formaking pillars of vehicles appear transpar tion the
half mirror. Light reflected from the object located on
object -side of the cloaking assembly passes through the
ent. cloaking assembly by reflecting off of a first outward facing
BACKGROUND mirror surface, a first half mirror oriented generally parallel
20 to the first outward facing mirror surface, a second half
Studies on cloaking devices that appear to make a pillar mirror oriented generally orthogonal to the first half mirror
of a vehicle transparent have been published . Such studies and a second outward facing mirror surface oriented gener
disclose the use ofmetamaterials or the use ofvideo cameras ally parallel to the second half mirror. Light that passes
in combination with a display screen to allow an occupant of through the cloaking assembly forms an image of the object
a vehicle to ostensibly " see ” though the vehicle pillar, 25 on the image - side of the cloaking assembly .
thereby reducing blind spots in the vehicle . However, meta - In embodiments , the cloaking device with the cloaking
materials and video technology use complicated material assembly has an end surface oriented non - planar to a half
designs and equipment. mirror. Light from an item located adjacent to the end
Accordingly , a need exists for alternative devices that surface passes through the cloaking assembly and forms an
appear to make a pillar of a vehicle transparent. 30 image of the item on the image side of the cloaking
assembly.
SUMMARY These and additional features provided by the embodi
ments described herein will be more fully understood in
In one embodiment, a cloaking device includes cloaking view of the following detailed description in conjunction
region (CR ) boundary planes oriented non -planar to each 35 with the drawings.
other and each of the CR boundary planes has an outward
facing mirror surface and an inward facing opaque surface . BRIEF DESCRIPTION OF THE DRAWINGS
The cloaking device includes a CR at least partially bounded
by the inward facing opaque surfaces of the CR boundary The embodiments set forth in the drawings are illustrative
planes . The cloaking device includes half mirrors spaced 40 and exemplary in nature and not intended to limit the subject
apart from and generally parallel to the outward facing matter defined by the claims. The following detailed descrip
mirror surfaces such that a half mirror is spaced apart from tion of the illustrative embodiments can be understood when
and generally parallel to each outward facing mirror surface . read in conjunction with the following drawings , where like
An article positioned within the CR is not visible outside of structure is indicated with like reference numerals and in
the CR and light reflected from an object on one side of the 45 which :
cloaking device is redirected around the CR and the article FIG . 1 schematically depicts a top view of a cloaking
positioned within the CR , and forms an image of the object device according to one or more embodiments described and
on another side of the cloaking device . illustrated herein ;
According to another embodiment, a cloaking device for FIG . 2 schematically depicts top isolated views of four
cloaking an article of a vehicle includes a cloaking assembly 50 cloaking device components of the cloaking device of FIG .
with an object -side, an image -side and at least two CR 1 according to one or more embodiments described and
boundary planes positioned at least partially between the illustrated herein ;
object-side and the image -side . The at least two CR bound- FIG . 3 schematically depicts a top perspective view of the
ary planes are positioned non - planar to each other and each cloaking device of FIG . 1 with a first object on one side of
of the at least two CR boundary planes have an outward 55 the cloaking device and a second object within a cloaking
facing mirror surface and an inward facing opaque surface . region (CR ) of the cloaking device ;
A CR is bounded by the inward facing opaque surfaces of FIG . 4 schematically depicts a side view of the cloaking
the at least two CR boundary planes and a vehicle article device of FIG . 3 with the first object on one side of the
positioned within the CR is not visible from outside the CR . cloaking device and the second object within the CR of the
The cloaking assembly has at least two half mirrors posi - 60 cloaking device ;
tioned at least partially between the object- side and the FIG . 5 schematically depicts a top view of a cloaking
image - side . Each of the at least two half mirrors is spaced device according to one or more embodiments described and
apart from and generally parallel to one of the outward illustrated herein ;
facing mirror surfaces such that a halfmirror is spaced apart FIG . 6 schematically depicts a top perspective view of the
from and generally parallel to each outward facing mirror 65 cloaking device of FIG . 5 with a first object on one side of
surface . Light from an object located on the object-side of the cloaking device and a second object and a third object
the cloaking assembly , and obscured by the vehicle article within a CR of the cloaking device;
 US 9,971, 162 B2
FIG . 7 schematically depicts a side view of the cloaking to be reflected or , alternatively, allows s-polarized light to
device of FIG . 6 with the first object on one side of the pass through and p -polarized light to be reflected . Referring
cloaking device and the second object and the third object to the coordinate system in the figure , portions of a target
within the CR of the cloaking device ; object are located directly behind the CR in the + Y direction
FIG . 8 schematically depicts a top isolated view of two 5 ( obscured portions of the object which are otherwise not
cloaking device components according to one or more visible through the CR ) and portions of the target object are
embodiments described and illustrated herein ; located outside or beyond the CR in the + Y direction ( visible
FIG . 9 schematically depicts a top view of a cloaking portions of the object ). Light rays (light) from the obscured
device with four cloaking device components according to portions of the target object travel in the - Y direction and are
one or more embodiments described and illustrated herein ; 10 incident on a first outward facing mirror surface . The first
FIG . 10 schematically depicts a side view of the cloaking outward facing mirror surface reflects the incident light from
device shown in FIG . 9 ; the obscured portions of the target object in the + X direction
FIG . 11 schematically depicts a top isolated view of two to a first half mirror that is spaced apart from and oriented
cloaking device components according to one or more generally parallel to the first outward facing mirror surface .
embodiments described and illustrated herein ; 15 Onemode of polarized light ( e.g ., p - polarized light) from the
FIG . 12 schematically depicts a top view of a cloaking light reflected from the first outward facing mirror surface
device with four cloaking device components according to passes through the first half mirror (continues traveling in
one or more embodiments described and illustrated herein ; the + X direction ), while another mode of polarized light
FIG . 13 schematically depicts a side view of the cloaking ( e .g . s -polarized light ) is reflected by the first half mirror in
device of FIG . 12 ; 20 the - Y direction . The polarized light reflected in the - Y
FIG . 14 schematically depicts a top isolated view of two direction by the first half mirror is reflected into the - X
cloaking device components according to one or more direction by a second half mirror. The polarized light
embodiments described and illustrated herein ; reflected into the - X direction by the second half mirror is
FIG . 15 schematically depicts a top view of four cloaking reflected in the - Y direction by a second outward facing
device components according to one or more embodiments 25 mirror surface that is spaced apart from and oriented gen
described and illustrated herein ; erally parallel to the second halfmirror . An observer looking
FIG . 16 schematically depicts a side view of the cloaking at the cloaking device in the + Y direction will see the
device of FIG . 15 ; reflection of the polarized light by the second outward facing
FIG . 17 schematically depicts a side view of a cloaking mirror surface , i.e. polarized light originating from light
device cloaking an A -pillar of a vehicle according to one or 30 from obscured portions of the target object will be visible to
more embodiments described and illustrated herein ; a human eye located on an opposite side of the CR from the
FIG . 18 schematically depicts a top view of a cloaking obscured portions of the target object . Also , light reflected
device according to one or more embodiments described and from an article positioned within the CR (i.e ., the cloaked
illustrated herein ; and article ) is not transmitted through the inward facing opaque
FIG . 19 schematically depicts a top view of a cloaking 35 surfaces and is not seen by the observer looking at the
device with four cloaking device components according to cloaking device in the + Y direction . That is, the cloaking
one or more embodiments described and illustrated herein . device effectively redirects light from the obscured portions
of the target object around the CR such that the light from
DETAILED DESCRIPTION the target object appears to pass through the cloaked article
40 giving the visual impression that the cloaked article is not
A cloaking device is provided . The cloaking device may present. Light from the visible portions of the target object
have an object-side, an image -side and a cloaking region travels in the - Y direction and is incident on the first half
(CR ) boundary plane having an outward facing mirror mirror. One mode of the incident light (e . g ., s -polarized
surface and an inward facing opaque surface . A CR is at least light ) is reflected in the + X direction by the first half mirror
partially bounded by the inward facing opaque surface of the 45 and another mode of the incident light ( e . g . p -polarized
CR boundary plane and a half mirror is spaced apart from light) is transmitted through the first half mirror and con
and generally parallel to the outward facing mirror surface . tinues traveling in the - Y direction . The transmitted polar
The half mirror may be a p - polarization half mirror or an ized light traveling in the - Y direction reaches the second
s -polarization half mirror. In embodiments , an article , e. g . an half mirror and is transmitted through the second halfmirror.
A -pillar of a vehicle , a B -pillar of a vehicle or a C -pillar of 50 An observer looking at the cloaking device in the + Y
a vehicle , is positioned within the CR and light from an direction will see the transmitted polarized light traveling in
object located on the object -side of the cloaking device and the - Y direction , i.e . polarized light originating from light
obscured by the CR is redirected around the CR and the from visible portions of the target object will be visible to a
article and forms the image of the object on the image -side human eye located on an opposite side of the cloaking
of the cloaking device such that the article appears trans - 55 device from the visible portions of the target object. Accord
parent. Various embodiments of cloaking devices and meth ingly , an individual will see the entire target object, both
ods for using the same will be described in further detail obscured portions and visible portions , that is located on the
herein with specific reference to the appended drawings. opposite side of the CR ( and thus on the opposite side of a
FIG . 1 generally depicts one embodiment of a cloaking cloaked article ) giving the visual impression that the cloaked
device . The cloaking device includes a cloaking region (CR ) 60 article is transparent .
that is at least partially bounded by at least two CR boundary Referring now to FIGS. 1 -2 , embodiments of a cloaking
planes that are non -planar to each other. Each of the two CR device include a cloaking assembly 10 with four CR bound
boundary planes has an outward facing mirror surface and ary planes 118 , 128 , 138 , 148 . The CR boundary planes 118 ,
an inward facing opaque surface . Spaced apart from and 128 , 138, 148 located adjacent to each other are non -planar
oriented generally parallel to each of the CR boundary 65 to each other. In embodiments, opposing CR boundary
planes is a half mirror (e .g ., a polarizing half mirror ) that planes 118 , 148 and 128 , 138 may be oriented parallel to
allows p -polarized light to pass through and s-polarized light each other and adjacent CR boundary planes 118 , 128 , 138 ,
 US 9,971, 162 B2
148 may be oriented orthogonal to adjacent CR boundary (- X direction ) of the half -mirror 125 , the optical filter 145a
planes, e .g. CR boundary plane 118 is oriented orthogonal to is positioned to the left (- X direction ) of the half -mirror 145 ,
adjacent CR boundary planes 138 , 128, CR boundary plane and the optical filter 145b is positioned to the right ( + X
128 is oriented orthogonal to adjacent CR boundary planes direction ) of the half-mirror 145 . The one or more optical
118 , 148 , etc. Each of the four CR boundary planes has an 5 filters 125a , 125b , 145a, 145b may be quarter -wave plates
outward facing mirror surface 118a , 128a, 138a, 148a, that convert linearly polarized light into circularly polarized
respectively , and an inward facing opaque surface 118h , light, or in the alternative , the one or more optical filters
128b , 1386, 148b , respectively . The outward facing mirror 125a , 125b , 145a , 145b may be a quarter -wave plate and a
surfaces 118a, 128a , 138a , 148a , can be made from omni - linear polarizer that convert linearly polarized light of one
directional photonic crystals or mirrors such that approxi- 10 mode, e . g ., S -mode or p -mode, into circularly polarized
mately 100 % ( + / - 10 % ) of light incident on the outward light, and then convert the circularly polarized light into a
facing mirror surfaces is reflected from the outward facing different linearly polarized mode , e .g., p -mode or s-mode ,
mirror surfaces. Accordingly , the term “ mirror surface ” used respectively.
herein refers to a surface that reflects approximately 100 % The CR boundary planes 118 , 138 are oriented at an angle
( + / - 10 % ) of all modes of light (e . g . S -polarized light and 15 , relative to the outward facing surfaces 112 , 132 , respec
p -polarized light) incident on the mirror surface . In embodi- tively , and the CR boundary planes 128 , 148 are oriented at
ments, the CR boundary planes 118 , 128 , 138 , 148 form a an angle ß , relative to the outward facing surfaces 122 , 142 ,
CR 200 bound at least partly by the inward facing opaque respectively. In embodiments , the angle , is equal to the
surfaces 118b , 128b , 138b , 148b . The four CR boundary angle ß , . In other embodiments , the angle , is not equal to
planes 118 , 128 , 138 148 , have a height ' h ' (FIG . 4 ) in the 20 the angle B1. The half mirrors 115 , 135 are oriented at an
Z direction of the coordinate axes in the figures and light angle 0 , relative to the outward facing surfaces 112 , 132,
reflected or transmitted within the CR 200 does not pass respectively , and the half mirrors 125 , 145 are oriented at an
through the inward facing opaque surfaces 118b , 128b , angle B2 relative to the outward facing surfaces 122, 142 ,
138b , 148b . Accordingly, an article ( e .g ., a cloaked article ) respectively. In embodiments, the angle 02 is equal to the
located within the CR 200 is not visible to an observer 25 angle B2. In other embodiments , the angle is not equal to
viewing the cloaking assembly 10 in the + Y direction . the angle Bz. In embodiments , the angle e , is equal to the
Still referring to FIGS. 1 and 2 , spaced apart from and angle 0 , and the angle B , is equal to the angle B2. For
oriented generally parallel (within + / - 2° ) to the four CR example , 0 , and 0 , can be generally equal to 45° ( + / - 1°) ,
boundary planes 118 , 128, 138 148 , are half mirrors 115 , and ß , and B2 can be generally equal to 45° ( + / - 10 ).
125 , 135 , 145 , respectively. The half-mirrors 115 , 125 , 135 , 30 The four cloaking assembly components 110 , 120 , 130 ,
145 reflect a specific mode of visible light Specifically, each 140 are transparent to incident light (both polarized and
of the half mirrors 115 , 125 , 135 , 145 can be an s -polarizer unpolarized ) except for the halfmirrors 115 , 125 , 135 , 145 ,
halfmirror or a p - polarizer halfmirror. The half mirrors 115 , the outward facing mirror surfaces 118a , 128a, 138a , 148a ,
125 , 135 , 145 can be in the form of a diffraction grating or the inward facing opaque surfaces 118b , 1286 , 1386, 1486 ,
thin film polarizer that reflects the s -mode of visible light 35 and optionally the outer end surfaces 116 , 126 , 136 , 146 . The
and allows the p -mode of visible light to pass through (a four cloaking assembly components 110 , 120 , 130 , 140 can
p -polarization diffraction grating or thin film ), or in the be made from any suitable transparent material, for example
alternative , reflects the p -mode of visible light and allows a transparent glass or a transparent plastic . In the alternative ,
the s -mode of the visible light to pass through (an s -polar- the four cloaking assembly components 110 , 120 , 130 , 140
ization diffraction grating or thin film ). It should be appre - 40 can be a structure , e . g . a frame, that holds the four CR
ciated that the half mirrors 115 , 125 are both s -polarizer half boundary planes 118 , 128 , 138 , 148 , and the four half
mirrors or p - polarizer half mirrors and the half mirrors 135 , mirrors 115 , 125 , 135 , 145 in a desired orientation relative
145 are both s -polarizer half mirrors or p - polarizer half to each other with air or another gas present between the four
mirrors , i.e . the half mirrors 115 , 125 may be s -polarizer CR boundary planes 118 , 128 , 138, 148 , and the four half
mirrors and the halfmirrors 135 , 145 may be p -polarizer half 45 mirrors 115 , 125 , 135 , 145 . The framemay be a plurality of
mirrors ; the half mirrors 115 , 125 may be p - polarizer mirrors transparent glass or transparent plastic panes that hold the
and the half mirrors 135 , 145 may be s -polarizer half four CR boundary planes 118 , 128 , 138 , 148 , and the four
mirrors; or all of the half mirrors 115 , 125 , 135 , 145 may be half mirrors 115 , 125 , 135 , 145 in a desired orientation
S -polarizer half mirrors or p - polarizer half mirrors . relative to each other with air or another gas present between
The four CR boundary planes 118 , 128 . 138 148 , and the 50 the four CR boundary planes 118 , 128 , 138 , 148 , and the
corresponding half mirrors 115 , 125 , 135 , 145 , may be part four half mirrors 115 , 125 , 135 , 145 . In embodiments ,
of four cloaking assembly components 110 , 120 , 130 , 140, transparent glass or transparent plastic panes form the out
respectively . Each of cloaking assembly components 110 , ward facing surfaces 112 , 122 , 132 , 142 , inward facing
120 , 130 , 140 has an outward facing surface 112 , 122 , 132 , surfaces 114 , 124 , 134 , 144 , and outer end surfaces 116 , 126 ,
142, respectively , an inward facing surface 114 , 124 , 134 , 55 136 , 146 , and hold the four CR boundary planes 118 , 128 ,
144, respectively, an outer end surface 116 , 126 , 136 , 146 , 138 , 148 , and the four half mirrors 115 , 125 , 135 , 145 in a
respectively , and an inner side surface defined by the inward desired orientation relative to each other with air or another
facing opaque surface 118b , 128b , 1386 , 148b , respectively . gas present between the four CR boundary planes 118 , 128 ,
The outward facing surfaces 112 , 132 form an object- side 138, 148 , and the four half mirrors 115 , 125 , 135 , 145 .
102 of the cloaking device and the outward facing surfaces 60 The outer end surfaces 116 , 126 , 136 , 146 may be
122, 142 form an image -side 104 of the cloaking device . transparent, have an absorber layer disposed thereon or be a
One or more optical filters 125a , 125b may be positioned on half-mirror. In embodiments, the outer end surfaces 116 ,
or adjacent to the outward facing surface 122 and one or 126 , 136 , 146 are transparent. In other embodiments , the
more optical filters 145a , 145b may be positioned on or outer end surfaces 116 , 126 , 136 , 146 have an absorber layer
adjacent to the outward facing surface 142. The optical filter 65 disposed thereon that absorbs incident light from within the
125a is positioned to the right ( + X direction ) of the half - four cloaking assembly components 110 , 120 , 130 , 140 ,
mirror 125 , the optical filter 125b is positioned to the left and /or from outside the four cloaking assembly components
 US 9,971 ,162 B2
110 , 120 , 130 , 140. The absorber layer may be made from The s-polarized light is reflected in the - X and + X directions
any suitable material that absorbs approximately 90 % (+ / - is incident on the outward facing mirror surfaces 128a ,
10 % ) of incident light, illustratively including dark colored 148a, respectively, and the outward facing mirror surfaces
surfaces made of glass, polymers, metals, ceramics , com - 128a , 148a reflect the incident s -polarized light is into the
posites, etc . In other embodiments, the outer end surfaces 5 - Y direction . The s -polarized light reflected into the - Y
116 , 126 , 136 , 146 are half-mirrors such that one mode of direction by the outward facing mirror surfaces 128a , 148a ,
incident light is reflected ( e . g ., s -polarized light or p -polar- forms an image of the obscured portion of the target object
ized light) and another mode of incident light is transmitted located directly above the CR 200 in the + Y direction that is
through the halfmirror ( e . g ., p - polarized light or s - polarized visible to an observer viewing the image -side 104 of the
light, respectively ) . In other embodiments, one or more of 10 cloaking assembly 10 . In embodiments , the optical filter
the outer end surfaces 116 , 126 , 136 , 146 is transparent and 125b , the optical filter 145b , or both optical filters 125b ,
one or more of the outer end surfaces 116 , 126 , 136 , 146 has 145b may be positioned on or adjacent to the outward facing
an absorber layer disposed thereon . In other embodiments , surfaces 122 , 142, respectively, as described above , and may
one or more outer end surfaces 116 , 126 , 136 , 146 is convert the s -polarized light reflected into the - Y direction
transparent and one or more of the outer end surfaces 116 , 15 by the outward facing mirror surfaces 128a , 148a , into
126 , 136 , 146 is a half mirror. In other embodiments, one or circularly polarized light or p -polarized light. For example ,
more of the outer end surfaces 116 , 126 , 136 , 146 has an the optical filter 125b the optical filter 145b , or both optical
absorber layer disposed thereon and one ormore of the outer filters 125b , 145b may be quarter wave plates that convert
end surfaces 116 , 126 , 136 , 146 is a half mirror. In other the s -polarized light reflected into the - Y direction by the
embodiments, one or more of the outer end surfaces 116 , 20 outward facing mirror surfaces 128a , 148a into circularly
126 , 136 , 146 is transparent, one or more of the outer end polarized light (not shown ) before forming the image of the
surfaces 116 , 126 , 136 , 146 has an absorber layer disposed obscured portion of the target object ' O ' located directly
thereon , and one ormore of the outer end surfaces 116 , 126 , above the CR 200 in the + Y direction . In the alternative, the
136 , 146 is a half mirror. optical filter 125b , the optical filter 145b , or both optical
While FIGS. 1 - 2 illustrate four cloaking assembly com - 25 filters 125b, 145b may be a quarter-wave plate and a linear
ponents 110 , 120 , 130 , 140, it should be appreciated that the polarizer that converts the s-polarized light reflected into the
four CR boundary planes 118 , 128 , 138 , 148 , and the four - Y direction by the outward facing mirror surfaces 128a ,
half mirrors 115 , 125 , 135 , 145 can be contained within any 148a into circularly polarized light (not shown) and then
number of cloaking assembly components . For example , in converts the circularly polarized light into p - polarized light
embodiments , the cloaking assembly components 110 and 30 before forming the image of the obscured portion of the
120 may be a single cloaking assembly component with no target object ' O ’ located directly above the CR 200 in the + Y
inward facing surface 114 , 124 , between the outward facing direction .
surfaces 112 , 122 , and the cloaking assembly components Light lo reflected from the visible portions of the target
130 and 140 may be a single cloaking assembly component object ' O ' not located directly behind the CR in the + Y
with no inward facing surface 134 , 144 , between the out- 35 direction is incident on and transmitted through the outward
ward facing surfaces 132 , 142. In other embodiments, the facing surfaces 112 , 132 . The transmitted light lo is incident
cloaking assembly components 110 and 130 may be a single on the p -polarization half mirrors 115 , 135 . The half mirrors
cloaking assembly component and the two cloaking assem - 115 , 135 reflect the s -mode is of the incident light lo in the
bly components 120 and 140 can be a single cloaking + X and - X directions , respectively, and transmit the p -mode
assembly component. In other embodiments , three of the 40 lp of the incident light lo in the - Y direction . The p -polarized
four cloaking assembly components 110 , 120 , 130 , 140 may light lp transmitted through the halfmirrors 115 , 135 will be
be a single cloaking assembly component assembled with a incident on and be transmitted through the p -polarization
remaining one of the cloaking assembly components 110, half mirrors 125 , 145 , respectively , in the - Y direction . The
120 , 130 , 140. For example , the three cloaking assembly p -polarized light lp transmitted in the - Y direction by the
components 110 , 120 , 130 may be a single cloaking assem - 45 half mirrors 125 , 145 forms an image of the visible portions
bly component assembled with the remaining cloaking of the target object O not located directly behind the CR 200
assembly component 140 . In other embodiments , the four in the + Y direction that is visible to an observer viewing the
cloaking assembly components 110, 120 , 130 , 140 may be cloaking assembly in the + Y direction . In embodiments, the
a single cloaking assembly component. optical filter 125a , the optical filter 145a , or both optical
Still referring to FIGS. 1 - 2 , light ' lo ’ is reflected from an 50 filters 125a , 145a may be positioned on or adjacent to the
object ' O ' (e . g ., a target object) located on the object- side outward facing surfaces 122 , 142 , respectively , as described
102 of the cloaking device, travels in the - Y direction , and above , in order to convert the p - polarized light into circu
is incident on and transmitted through the outward facing larly polarized light of s-polarized light. For example , the
surfaces 112 , 132 . The light lo reflected from the obscured optical filter 125a , the optical filter 145a or both optical
portions of the object 'O ’ located directly behind the CR in 55 filters 125a , 145a may be quarter wave plates that convert
the + Y direction is reflected by the outward facing mirror the p -polarized light transmitted into the - Y direction by the
surfaces 118a , 138a in the + X and - X directions, respec half mirrors 125 , 145 into circularly polarized light ( not
tively . The light lo reflected in the + X and - X directions is shown ) before forming the image of the visible portions of
incident on the half mirrors 115 , 135 respectively . As illus - the target object ' O ' not located behind above the CR 200 in
trated in FIG . 1 , the half mirrors 115 , 135 are p - polarization 60 the + Y direction . In the alternative , the optical filter 125a ,
half mirrors that reflect the s-mode ( ls ) of the light lo and the optical filter 145a, or both optical filters 125a , 145a may
allow the p -mode ( ip ) of the light lo to pass through . The be a quarter -wave plate and a linear polarizer that convert
s -polarized light is reflected from the half mirrors 115 , 135 the p -polarized light reflected into the - Y direction by the
in the - Y direction is incident on the half mirrors 125 , 145 , outward facing mirror surfaces 128a , 148a into circularly
respectively. The half mirrors 125 , 145 are also p -polariza - 65 polarized light (not shown ) and then convert the circularly
tion mirrors that reflect the s - polarized light ls traveling in polarized light into s -polarized light before forming the
the - Y direction into the - X and + X directions, respectively . image of the visible portions of the target object 'O ' not
 US 9,971, 162 B2
10
located directly above the CR 200 in the + Y direction . distance ‘d ' is between the inward facing surfaces 114 , 124 ,
Accordingly, an image ‘ l’ of the entire target object ' O ’ (both and between the inward facing surfaces 134 , 144. The area
the obscured portion and the visible portions ) is visible to the of the CR 200 in the X - Y plane is increased by the width ' w '
observer viewing the image - side 104 of the cloaking assem - times the distance d (wxd ). The volume of the CR 200 is
bly 10 . While half mirrors 115 , 125 , 135 , 145 are described 5 increased by the width w times the distance d times the
herein as p -polarization half mirrors, it should be appreci- height h (FIG . 4 ) of the CR 200 (wxdxh ). While FIG . 5
ated that half mirrors 115 , 125 , 135 , 145 can be s -polariza - illustrates four cloaking assembly components 110 , 120 ,
tion half mirrors and the reflected and transmitted portions 130 , 140, it should be appreciated that the four CR boundary
of the reflected light lo discussed above will be reversed . planes 118 , 128, 138 , 148 , and the four half mirrors 115 , 125 ,
However, the human eye cannot distinguish between s -po - 10 135 , 145 can be contained within any number of cloaking
larized light, p -polarized light or circularly polarized light assembly components. For example , in embodiments , the
and the image ‘ I' of the entire object ' O ' will be visible to cloaking assembly components 110 and 130 may be a single
the human eye when an observer is viewing the image - side cloaking assembly component and the two cloaking assem
104 of the cloaking assembly 10 . Also , it should be appre - bly components 120 and 140 can be a single cloaking
ciated that the one or more of optical filters 125a, 1256 , 15 assembly component.
145a , 145b may be positioned on or adjacent to outward As shown in the FIG . 5 , light lo is reflected from the target
facing surfaces 122 , 142 as described above such that only object O , travels in the - Y direction and is incident on and
p -polarized light forms the image ‘ I', only s -polarized light transmitted through the outward facing surfaces 112 , 132 .
forms the image ' I', only circularly polarized light forms the Light lo reflected from the obscured portions of the object
image 'I', only p -polarized light and circularly polarized 20 located directly behind the CR in the + Y direction is
light form the image ‘I' or only s -polarized light and reflected by the outward facing mirror surfaces 118a , 138a
circularly polarized light form the image “ I'. Such manipu in the + X and - X direction , respectively . The reflected light
lation of the polarized light reflected into the - Y direction by lo in the + X and - X directions is incidenton the halfmirrors
the outward facing mirror surfaces 128a , 128a and the 115 , 135 respectively . The half mirrors 115 , 135 are p - po
polarized light transmitted in the - Y direction by the half 25 larization half mirrors and reflect the s -mode is of the light
mirrors 125 , 145 may assist an observer wearing polarized lo and transmit the p -mode lp of the light lo . The s -polarized
sunglasses in viewing the image -side 104 of the cloaking light is reflected by the half mirrors 115 , 135 in the - Y
assembly 10 . Particularly , the one or more optical filters direction is incident on the half mirrors 125 , 145 , respec
125a, 1256 , 145a, 145b ensure that polarized sunglasses that tively . The half mirrors 125 , 145 are also p -polarization
block p -polarized light or s -polarized light do not prevent an 30 mirrors that reflect the s- polarized light is traveling in the - Y
observer wearing such polarized sunglasses from seeing the direction into the - X and + X directions , respectively . The
entire target object ' O ' when viewing the image -side 104 of S-polarized light Is traveling in the - X and + X directions is
the cloaking assembly 10 . incident on the outward facing mirror surfaces 128a, 148a ,
Referring now to FIGS . 1 -4 , a top perspective view and a respectively , and the outward facing mirror surfaces 128a ,
side view of a cloaking device according to embodiments ( as 35 148a reflect the incident s -polarized light ls in the - Y
discussed with respect to FIGS. 1 - 2 ) are shown in FIGS. 3 - 4 , direction . The s -polarized light reflected in the - Y direction
respectively. Specifically, FIG . 3 is a top perspective view of by the outward facing mirror surfaces 128a , 148a , forms an
an article in the form of a column ' C ' within the CR 200 of image of the obscured portion of the object located behind
the cloaking assembly 10 and an automobile ‘ A ’ located the CR 200 in the + Y direction that is visible to an observer
behind the column C on the object-side 102 of the cloaking 40 viewing the image - side 104 of the cloaking assembly 12 .
assembly 10 in the + Y direction . The column C has a height Light lo reflected from the visible portions of the target
dimension in the Z direction ( increasing height in the - Z object O not located behind the CR 200 in the + Y direction
direction ) greater than the height h of the cloaking device . is incident on and transmitted through the outward facing
FIG . 4 is a side view from the + Y direction of the cloaking surfaces 112 , 132 . The transmitted light lo is incident on the
assembly 10 shown in FIG . 3 and shows the portion of the 45 p -polarization half mirrors 115 , 135 , and the half mirrors
column C that is within the CR 200 is not visible and the 115 , 135 reflect the s -mode is of the incident light lo in the
automobile A located behind the column C in the + Y + X and - X directions, respectively , and transmit the p -mode
direction is visible to an observer viewing the cloaking lp of the incident light lo in the - Y direction . The p -polarized
assembly 10 in the + Y direction . Accordingly , the column C light lp transmitted through the half mirrors 115 , 135 in the
positioned within the CR 200 is not visible to an observer 50 - Y direction is incident on and transmitted through the
viewing the image - side 104 of the cloaking assembly 10 and p - polarization half mirrors 125 , 145 , respectively , in the - Y
an image of the entire automobile A (both the obscured direction . The p -polarized light lp transmitted in the - Y
portion and the visible portions ) is visible to the observer direction through the halfmirrors 125 , 145 , forms an image
viewing the image- side 104 . Although column C in FIGS. of the visible portions of the target object O not located
3 - 4 is separate from the CR boundary planes 118 , 128 , 138 , 55 behind the CR 200 in the + Y direction that is visible to an
148, i. e ., column C is a separate object from the cloaking observer viewing the image side 104 of the cloaking assem
device 10 , it should be appreciated that column C may be bly 12 . Accordingly, an image I of the entire target object O
structurally part of the cloaking device 10 and have an outer (both the obscured portion and the visible portions) is visible
surface that provides or is equivalent to the CR boundary to an observer viewing the image -side 104 of the cloaking
planes 118 , 128 , 138 , 148 with outward facing mirror 60 assembly 12 . It should be appreciated that half mirrors 115 ,
surfaces 118a , 128a , 138a, 148a , respectively. 125 , 135 , 145 , can be s- polarization half mirrors and the
Referring now to FIGS. 1 -5 , FIG . 5 shows embodiments reflected and transmitted portions of the reflected light lo
of a cloaking assembly 12 with an enlarged CR 200. discussed above will be reversed . Also , it should be appre
Particularly , the cloaking assembly components 110 , 120 ,
ciated that the one or more of optical filters 125a , 125b ,
130 , 140 are arranged such that the cloaking assembly 65 145a, 145b may be included . However, the human eye
components 110, 130 are spaced apart in the Y direction cannot distinguish between s - polarized light, p -polarized
from the cloaking assembly components 120 , 140 , and a light or circularly polarized light and the image 1 of the
 US 9 ,971, 162 B2
12
entire object O will be visible to an observer viewing the Referring to FIGS. 1 - 10 , embodiments of a cloaking
image-side 104 of the cloaking assembly 12 . device with a cloaking assembly 14 having items in the form
Referring now to FIGS. 1 -7 , a top perspective view and a of ' 1 ', ' 2 ', '3 ', '4 ' adjacent to the outer end surfaces 126 ,
side view of a cloaking device according to embodiments (as 146 , 116 , 136 , respectively are shown in FIG . 9 . FIG . 10 is
discussed with respect to FIG . 5 ) are shown in FIGS. 6 -7 , 5 a side view of the cloaking assembly 14 illustrated in FIG .
respectively . Specifically , FIG . 6 is a top perspective view of 9 with reversed images of item 1 and item 2 , in conjunction
with the image of the automobile A , visible on the image
a first article in the form of a column 'C1' and a second side 104 of the cloaking assembly 14 . It should be appre
article in the form of a column ‘C2'within the CR 200 of the ciated that items 1, 2 , 3 , 4 depicted in FIGS. 9 - 10 are shown
cloaking assembly 12 and the automobile ‘ A ’ located behind
10 for illustrative
the columns C1, C2 on the object-side 102 of the cloaking could be oriented purposes only , i.e . the items 1, 2 in FIG . 9
assembly 12 in the + Y direction . The column C1 has a first reversed images of initems the Y - Z plane in order to provide
height dimension in the Z direction and the column C2 has plane ) in FIG . 10 . It should 1,also2 onbethe image side 104 ( X - Z
appreciated that reversed
a second height dimension that is greater ( in the - Z direc images of item 3 and item 4 can be formed or provided on
tion ) than the first height dimension of column C1. The firstSt 15 the object -side 102 of the cloaking assembly 14 in a similar
height dimension of column C1 and the second height man as the reversed images of item 1 and item 2 are
manner
dimension of column C2 are both greater than the height h formed on the image - side 104 .
of the cloaking assembly 12 . FIG . 7 is a side view from the Referring to FIGS. 1- 8 and 11, embodiments of a cloaking
+ Y direction of the cloaking assembly 12 shown in FIG . 6 device that can selectively display images in conjunction
and shows the image- side 104 . Portions of column C1 and 20 with the images depicted in FIGS. 1 , 4 , 5 and 7 are shown.
column C2 within the CR 200 are not visible and automobile Particularly , FIG . 11 shows an item in the form of the
A located behind column C1 and column C2 in the + Y number ‘ l ’ and an item in the form of the number “2 ' located
direction is visible to an observer viewing the image - side adjacent to the outer end surfaces 126 , 146 , respectively , in
104 of the cloaking assembly 12 . Although columns C1, C2 the + X , - X directions , respectively . Light lo from item 1 is
in FIGS. 6 -7 are separate from the CR boundary planes 118 , 25 incident on an s- polarizer 150 . The s - polarizer 150 allows
128 , 138, 148, i.e ., columns C1, C2 are separate objects from the s -mode is of the incident light lo to pass through in the
the cloaking device 12 , it should be appreciated that columns - X direction . The s -polarized light ls is incident on and
C1, C2 may be structurally part of the cloaking device 12 reflected by the p -polarization half mirror 125 into the Y
and have an outer surface that provides or is equivalent to direction and no light is transmitted through or beyond the
the CR boundary planes 118 , 128 , 138 , 148 with outward 30 p - polarization half mirror 125 in the - X direction . Accord
facing mirror surfaces 118a , 128a , 138a , 148a, respectively . ingly , a reversed image of item 1 is formed only on the right
Referring to FIG . 8 , embodiments of a cloaking device hand side of the outward facing surface 122 . The light lo
that can display additional images in conjunction with the from item 2 is transmitted through the outer end surface 146
images depicted in FIGS. 1, 4 , 5 and 7 are shown . Particu - in the + X direction and is incident on the p -polarization half
larly , FIG . 8 shows an item in the form of the number ' 1 ' 35 mirror 145 . The p - polarization half mirror 145 transmits the
(item 1 ) and an item in the form of the number 62 ' (item 2 ) p -mode lp of the incident light lo in the + X direction and
located adjacent to the outer end surfaces 126 , 146 , respec - reflects the s -mode is of the incident light lo in the - Y
tively, in the + X , - X directions, respectively . Light lo direction . The p -polarized light lp in the + X direction is
reflected from item 1 and item 2 is incident on and trans - incident on the outward facing mirror surface 148a . The
mitted through the outer end surfaces 126 , 146 in the - X , + X 40 outer facing mirror surface 148a reflects the incident p -po
directions, respectively . The light lo transmitted through the larized light lp in the - Y direction . The s -polarized light ls
outer end surfaces 126 , 146 is incident on the half mirrors reflected by the half mirror 145 in the - Y direction forms a
125 , 145 , respectively . The half mirrors 125 , 145 (p - polar- reversed item 2 image on the left hand side of the outer
ization halfmirrors ) transmit the p -mode lp of the light lo in facing surface 142. The p -polarized light lp reflected by the
the - X , + X directions , respectively , and reflect the s -mode is 45 outer facing mirror surface 148a into the - Y direction
of the light lo into the - Y direction . The transmitted p -po - provides a reversed item 2 image on the right hand side of
larized light lp in the - X , + X directions is incident on the the outer facing surface 142 .
outward facing mirror surfaces 128a , 148a, respectively. Referring to FIGS. 1 -8 and 11 - 13 , embodiments of a
The outward facing mirror surfaces 128a , 148a , reflect the cloaking device with a cloaking assembly 16 having items in
incident p -polarized light lp into the - Y direction . The 50 the form of l ' and ' 2 ' adjacent to the outer end surfaces 126 ,
s - polarized light is reflected by the half mirror 125 in the - Y 146 , respectively , and the s -polarizer 150 adjacent the outer
direction forms a reversed ‘ l ' image on the right hand side end surface 126 , are shown in FIG . 12 . FIG . 13 is a side view
of the outward facing surface 122 and the s-polarized light of the cloaking assembly 16 illustrated in FIG . 12 with the
Is reflected by the half mirror 145 in the - Y direction forms reversed image of item 1 visible on the right hand side of the
a reversed “ 2 ’ image on the left hand side of the outer facing 55 outer facing surface 122 of the cloaking assembly compo
surface 142 . The p -polarized light lp reflected by the out- nent 120 and the reversed image of item 2 visible on the left
ward facingmirror surface 128a into the - Y direction forms hand side and right hand side of the outward facing surface
a reversed ‘ l ' image on the left hand side of the outward 142 of the cloaking assembly components 140 shown in
facing surface 122 and the p -polarized light lp reflected by conjunction with the image of the automobile A . It should be
the outward facing mirror surface 148a into the - Y direction 60 appreciated that items 1 , 2 depicted in FIG . 12 are shown for
formsa reversed ‘ 2 ’ image on the righthand side of the outer illustrative purposes only, i.e. the items 1, 2 in FIG . 12 could
facing surface 142 . It should be appreciated that the display be oriented in the Y -Z plane in order to provide the reversed
of additional images as depicted in FIG . 8 in conjunction images of items 1 , 2 on the image -side ( 104 ) ( X -Z plane )
with images as depicted in FIGS. 1 , 4 , 5 and 7 can be used shown in FIG . 13 .
as part of a heads-up display , a warning system ( signal) that 65 Referring to FIGS . 1 -8 and 14 , another embodiment of a
an object is located on the object side of the cloaking device , cloaking device that can selectively display additional
etc . images in conjunction with the images depicted in FIGS . 1,
 US 9,971, 162 B2
13 14
4 , 5 and 7 is shown. Particularly, FIG . 14 shows an item in A -pillar P and a blind spot typically created by the A -pillar
the form of the number ‘ l ’ and an item in the form of the Pis not present. In embodiments, the A -pillar P itself serves
number 62 ' located adjacent to the outer end surfaces 126 , as the CR 200, i.e . the A -pillar P has an outer surface with
146 , respectively, in the + X , - X directions , respectively. one or more outer facing mirror surfaces that assist in
Light lo reflected from the item 1 is incident on a p -polarizer 5 redirecting light from the pedestrian ) around the A -pillar P .
152 which allows p -polarized light lp to pass through in the It should be appreciated that cloaking of the A -pillar P with
- X direction . The p -polarized light lp is incident on the the cloaking device 19 and removing the blind spot pro
p -polarization half mirror 125 . The incident p -polarized duced by the A -pillar P is performed without the use of
light lp in the X direction is transmitted through the metamaterials, video images, cameras, sophisticated elec
p -polarization halfmirror 125 in the - X direction and there 10 tronics , etc .
is no s -polarized light is to be reflected by the p - polarization Referring to FIGS. 18 - 19 , alternative embodiments of
half mirror 125 in the - Y direction. The p - polarized light lp cloaking devices are shown. Specifically, FIG . 18 shows a
transmitted through the p -polarization half mirror 125 is cloaking device 20 with a circular CR 202 having an outer
incident on the outward facing mirror surface 128a and the mirror surface 204 with half mirrors 206 , 208 around the
outward facing mirror 128a reflects the p -polarized light lp 15 outer mirror surface 204 having a circular shape. In embodi
into the - Y direction . Accordingly , a reversed image of item ments, the CR 202 is provided by an object to be cloaked
1 is formed only on the left hand side of the outward facing itself, e .g ., an A -pillar, that has an outer mirror surface 204 .
surface 122 . The light lo reflected from item 2 is transmitted The cloaking device shown in FIG . 18 can increase the field
through the outer end surface 146 in the + X direction and is of view for an observer viewing the cloaking device 20 in
incident on the p -polarization half mirror 145 . The p -polar - 20 the + Y direction . FIG . 19 shows a cloaking device 30 with
ization half mirror 145 transmits the p -mode lp of the a circular CR 302 having an outer mirror surface 304 with
incident light lo in the + X directions and reflects the s -mode half mirrors 306 , 308 and optical components 310 , 312 such
ls of the incident light lo into the - Y direction . The p -po - as lenses . In embodiments , the CR 302 is provided by an
larized light lp in the + X is incident on the outer facing object to be cloaked itself, e . g ., an A -pillar, that has an outer
mirror surface 148a. The outer facing mirror surface 148a 25 mirror surface 304. The cloaking device shown in FIG . 19
reflects the incident p -polarized light lp into the - Y direc - allows for an external view from an object located behind
tion . The s -polarized light ls reflected by the half mirror 145 the CR 302 ( + Y direction ) to be manipulated to increase a
in the - Y direction forms a reversed 2 on the left hand side field of view or to normalize a distorted image .
of the outer facing surface 142 and the p - polarized light lp The cloaking devices described herein may be used to
reflected by the outer facing mirror surface 148a in the - Y 30 cloak vehicle articles such as a vehicle A - pillar, and remove
direction forms a reversed 2 image on the right hand side of a “ blind spot” caused by the vehicle article . It will be
the outer facing surface 142. understood that the term “blind spot” as used herein refers
Referring to FIGS. 1 -8 and 14 - 16 , embodiments of a to an area around the vehicle that cannot be directly
cloaking device with a cloaking assembly 18 having items 1 observed by a driver while operating the vehicle. The terms
and items 2 adjacent to the outer end surfaces 126 , 146 , 35 “ object," " article,” and “ item ” may interchangeably refer to
respectively , and the p -polarizer 152 adjacent to the outer a visual object or image (2D or 3D ) that reflects light or
end surface 126 , are shown in FIG . 15 . FIG . 16 is a side view transmits light and the team “ light from ” may refer to “ light
of the cloaking assembly 18 illustrated in FIG . 15 with the reflected from ” or “ light transmitted from .” The terms
single reversed image of item 1 visible on the left hand side “ generally," " approximately," and " about" may be utilized
of the outer facing surface 122 of the cloaking assembly 40 herein to represent the inherent degree of uncertainty that
component 120 and the reversed image of item 2 visible on may be attributed to any quantitative comparison , value,
the left hand side and right hand side of the outward facing measurement, or other representation . These terms are also
surface 142 of the cloaking assembly components 140 in utilized herein to represent the degree by which a quantita
conjunction with the image of the automobile A . It should be tive representation may vary from a stated reference without
appreciated that items 1 , 2 depicted in FIG . 15 are shown for 45 resulting in a change in the basic function of the subject
illustrative purposes only , i.e . the items 1 , 2 in FIG . 15 could matter at issue.
be oriented in the Y - Z plane in order to provide the reverse While particular embodiments have been illustrated and
images of items 1 , 2 on the image - side 104 ( X - Z plane ) described herein , it should be understood that various other
shown in FIG . 16 . changes and modifications may be made without departing
Referring to FIGS. 1 , 2 , 5 , 8 -17 , embodiments of an 50 from the spirit and scope of the claimed subject matter.
A - pillar of a vehicle being cloaked by a cloaking device are Moreover, although various aspects of the claimed subject
shown . Particularly, FIG . 17 shows a cloaking device 19 matter have been described herein , such aspects need not be
cloaking a portion of an A -pillar P of a vehicle V . A portion utilized in combination . It is therefore intended that the
of the A -pillar P is positioned within a CR 200 ( not shown) appended claims cover all such changes and modifications
of the cloaking device 19 and a portion of the A - pillar P 55 that are within the scope of the claimed subject matter.
extends beyond the cloaking device and is covered with trim What is claimed is:
T . Illustrated outside of the vehicle V is a target object O in 1 . A cloaking device comprising:
the form of pedestrian . A portion of the pedestrian O is an object-side and an image-side ;
visible through a side window of the vehicle V and a portion a cloaking region (CR ) boundary plane having an outward
of the pedestrian is visible “ through ” the A - pillar P cloaked 60 facing mirror surface and an inward facing opaque
by the cloaking device 19 . The cloaking device 19 redirects surface ;
light reflected from the pedestrian O around the A -pillar P a CR at least partially bounded by the inward facing
positioned within the CR 200 of the cloaking device 19 and opaque surface of the CR boundary plane;
forms an image I of the pedestrian O on an image - side 104 a half mirror spaced apart from and generally parallel to
of the cloaking device 19 that is visible to an occupant of the 65 t he outward facing mirror surface ;
vehicle V looking towards the pedestrian O . Accordingly , wherein light from an object located on the object -side of
light from the pedestrian O appears to pass through the the cloaking device and obscured by the CR is redi
 US 9 ,971 , 162 B2
15 16
rected around the CR to form an image of the object on at least two CR boundary planes having an outward
the image -side of the cloaking device such that the light facing mirror surface and an inward facing opaque
from the object appears to pass through the CR . surface;
2 . The cloaking device of claim 1, wherein the half mirror a CR bounded by the inward facing opaque surfaces of
is selected from a p -polarization half mirror and an s -polar- 5 the at least two CR boundary planes ;
ization half mirror. at least two half mirrors located at least partially
3. The cloaking device of claim 1, further comprising an between the object- side and the image -side , each of
article positioned within the CR , wherein the light from the the at least two half mirrors spaced apart from and
object located on the object-side of the cloaking device and generally parallel to one of the outward facing mirror
obscured by the CR is redirected around the CR and the 10 surfaces ;
article to form the image of the object on the image -side of at least one quarter -wave plate positioned on or adja
the cloaking device such that the article appears transparent. cent to the image side ;
4 . The cloaking device of claim 3, wherein the article is and
a vehicle A -pillar.
5 . The cloaking device of claim 1, further comprising: 15 a vehicle article positioned within the CR ;
at least two CR boundary planes positioned non - planar to wherein light from an object located on the object-side of
each other, each of the at least two CR boundary planes the cloaking assembly and obscured by the CR is
having an outward facing mirror surface and an inward redirected around the CR and forms an image of the
facing opaque surface , the CR at least partially object on the image - side of the cloaking assembly such
bounded by the inward facing opaque surfaces of the at 20 that the vehicle article appears to be transparent.
least two CR boundary planes ; 11 . The cloaking device of claim 10 , wherein the vehicle
at least one quarter-wave plate positioned on or adjacent article is a vehicle A -pillar.
to the image side ; and 12 . The cloaking device of claim 10 , wherein the light
at least two half mirrors spaced apart from and generally from the object is reflected by a first outward facing mirror
parallel to the outward facing mirror surfaces, respec - 25 surface , a first half mirror oriented generally parallel to the
tively ; such that a half mirror of the at least two half first outward facing mirror surface , a second half mirror
mirrors is spaced apart from and generally parallel to oriented generally orthogonal to the first half mirror and a
each of the outward facing mirror surfaces; second outward facing mirror surface oriented generally
wherein the light from the object located on the object - parallel to the second halfmirror and transmitted through the
side of the cloaking device and obscured by the CR is 30 at least one quarter -wave plate before forming the image on
redirected around the CR by the at least two outward the image -side of the cloaking assembly .
facing mirror surfaces and the at least two half mirrors, 13 . The cloaking device of claim 12 , further comprising
and the image of the object is formed on the image - side an end surface , wherein light from an item located adjacent
of the cloaking device such that the light from the to the end surface passes through the cloaking assembly and
object located on the object- side of the cloaking device 35 forms an image of the item on the image -side of the cloaking
appears to pass through the CR . assembly .
6 . The cloaking device of claim 5 , wherein the at least two 14 . The cloaking device of claim 13, wherein a p -mode or
CR boundary planes are positioned orthogonal to each other. an s-mode of the light from the item is reflected from the
7 . The cloaking device of claim 6 , wherein the light from second half mirror before forming the image of the item on
the object on the object-side of the cloaking device is 40 the image-side of the cloaking assembly .
reflected by a first outward facing mirror surface, a first half 15 . The cloaking device of claim 13 , wherein a p -mode or
mirror positioned parallel to the first outward facing mirror an s -mode of the light from the item is transmitted through
surface , a second half mirror positioned orthogonal to the the second half mirror and reflected by the second outward
first half mirror, a second outward facing mirror surface facing mirror surface before forming the image of the item
positioned parallel to the second halfmirror, and transmitted 45 on the image - side of the cloaking assembly .
through the at least one quarter-wave plate before forming 16 . A cloaking device comprising:
the image of the object on the image - side of the cloaking four cloaking region (CR ) boundary planes positioned
device . non -planar to each other, each of the four CR boundary
8 . The cloaking device of claim 7, further comprising a planes having an outward facing mirror surface and an
vehicle article positioned within the CR , wherein the light 50 inward facing opaque surface ;
from the object located on the object- side of the cloaking a CR bounded by the inward facing opaque surfaces of the
device and obscured by the CR is redirected around the CR four CR boundary planes;
and the vehicle article to form the image of the object on the an article located at least partially within the CR ;
image -side of the cloaking device and the vehicle article four half mirrors spaced apart from and generally parallel
appears transparent. 55 to the outward facing mirror surfaces, respectively ,
9 . The cloaking device of claim 5 , further comprising an such that a half mirror of the four half mirrors is spaced
end side, wherein light from an item positioned adjacent to apart from and generally parallel to each of the outward
the end side forms an image of the item on the image - side facing mirror surfaces ;
of the cloaking device . wherein light from an object on an object-side of the
10 . A cloaking device for cloaking an article of a vehicle 60 cloaking device is redirected around the CR and
comprising: appears as an image on an image - side of the cloaking
a cloaking assembly comprising: device and is visible to an observer viewing the image
an object- side and an image -side ; side of the cloaking device, and wherein the article
at least two cloaking region (CR ) boundary planes within the CR is not visible to the observer viewing the
located at least partially between the object- side and 65 image - side of the cloaking device such that the article
the image -side , the at least two CR boundary planes within the CR appears transparent to the observer
positioned non -planar to each other and each of the viewing the image- side of the cloaking device.
 US 9,971 ,162 B2
17
17 . The cloaking device of claim 16 , wherein the light
from the object is reflected by a first of the outward facing
mirror surfaces , a first of the outward facing mirror surfaces ,
a first of the four half mirrors oriented generally parallel to
the first outward facing mirror surface , a second half mirror 5
oriented generally orthogonal to the first half mirror and a
second outward facing mirror surface oriented generally
parallel to the second halfmirror before forming the image
on the image -side of the cloaking device .
18 . The cloaking device of claim 17 , wherein the article 10
is a vehicle A -pillar.
19. The cloaking device of claim 18 , further comprising
an end side , wherein light from an item located adjacent to
the end side is reflected by at least one of the second half
mirror and the second outward facing mirror surface and 15
forms an image of the item on the image - side of the cloaking
device .
20 . The cloaking device of claim 19, wherein the image
of the item is selectively formed on the image - side of the
cloaking device. 20
* * * *