Note: Descriptions are shown in the official language in which they were submitted.
~, Wo 90/16057 2 ~ 5 ~13 ~ Pcr/us9o/o333s
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' ~QD OF q~E INV~aN
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inverlt~ ~la~ to the ~iald o~ dlsE~la~ .
,~~ ar~l ~o~ t:~a b~l~ a~ a ~ t~noJ.~ ~ n~3w
, .
Ih~ po~tion~ o~ tho ~leld o~ display systems and o~othRr ~iel~ addr~s~6~ by the p~ese~ in~ention include consumer
and indu~trial video, pr~ction ~ideo, military and scienti~ic
display panel5, Golor ~ilter control5, and light sources. Ihe
term "dlsplay" as used herein includes displays and display-like
systems, unless o*herwise ;n~cated.
Ihe state of the art of display systems includes gelatin
or dyed polymide filter mat~rials associated with matrix light
source means with intensities of d~ play-transmission (as a
px~x~nt of saurce light) of ab3ut sixty for bluergreen spec*rzl
ranges and m nety for red. For a gcod review, see, e.g., Iatham
et al., ~Color Filters From Dyed Polymides~ Solid State
Tedhnolo~y pMay 1988). The state o~ the art also inClUdes active
~.,,
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~'' ' ~'.
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W O 9~/160~7 PCTIUS90/03335
~ 0 5 ~
-2~
matrix liquid crystal display (ICD) means. See, e.g., Sakai et
ali. (NTT), "A DefectJTolerant 5echnology ~or An Astive-Matrix
LCD Integrated With Peripheral Circuits~ SID (Society for
: Information Display) 88 Digest pp. 400 - 403. ~hin film diode or
.. :. transis~or light emitter arrays can be provided in similar
fashion. The foregoing publlcations are incorpo~ated herein by
reference as thcugh s~t out at length herein. ~ The present
i~ventlon prcvides ~ignl~icant bene~its compared to the s~ate of
', the art and camm~raial practice thereo~.
i,
u It i5 an object o~ the present invention to pravide,~ displays o~ high resoluticn dot area (pixel) selection, with high
intensity o~ color availability selectable avQr a large spectral
ra~gQ in cus~m tailored de~ign and production-
~,
. It is A ~urth~r ck~ect 0~ the in~nt~n to pr~vid~
~ ~ ei~h~ VQ percont-plu~ ~pro~rxably, ovar n~n~t~ F~ nk) llgh~
:;~. ~si~r th~cug~u~ ~ v~iblo c~i~al ~pec~ ~alu~ ~d,
blu~ een) ~nd ~rab~y al~o in t~ni~ ~pe~ rar~es
" l~on~ visible ~e.g., near ~ ar ~, uV) .
It i~ a ~her c~ect o~ t~ invE3ntlon to pra~ride sudh
~-............... di~plays o~ canpact otn~ form.
,; It is a ~er ~bject of the irn~ention to prcnride such
dis;plays wi~h lang life an~ lc~ failure vulnerab;l ity.
--: It is a ~urther cbject of the inv~nticn t~ prcvide such
displays economically and simply.
It is a further cbjeck of the invenkion to provide such
i displays with high ~peed o~ response to control signals and
~ si~nply ~c~ol ~ in c~inati~ t~itll.
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WO 90/~6057 2 0 5 ~ 1 3 a PCr/US90/03335
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It is a f~art~r bb~ect oî the invention to pmvide such
display free of parallax and/or anisotr~ lim~tations of its
~ptical characteris~ic.
It is a further ~bject of tha i2~ ion to provide such
~play wi~h a high degree of te~perature stability and/or
chemical ~tability ~ all cor~litions of marmfacture and ~se.
.. .. ...
Wo 90/16057 2 ~ 5 91~ a PCT/US90/U333~ ~
lhe cbjects of the invention are re21iz~d in a system
using thin f~lm technology to pr3vide a key color control section
and also using such technology for light oontrol steps other than
color ~;ltering.
me display system has a l~ght source and high
r~olution light control ~ er p~oducing selected dots o~ light
o~lglnation or passage at high resolution (or dots of light
blockag~ in an amblent of essentially collimatad light).
In its light passage embodiments, the system is
constructed ~nd arranged 80 ~hat a beam oP light impacts a ~hin
~i~m color c~ntrol parel and passes thxou~h it ~or is re~lected
by it), and pxeP~rrably al~o pas~es th~ough a pr~t~ctive
t3z~q>lrent ~ore~n, to a view~r. Ihe col~r cont~ol panel
ccmprlsa~ ~ highly adhQr~nt color r~pon~ m~t~ri~l, p~a~rrabl~
an ~nodically oxi~iz~d ~hin ~ilm Or ~antalum or ~n~alum nitrides
or other anodically oxldl~ible metal (valve me~al).
Pre~Qrrably, the color control and light ccntrol ~ilter
portions are inte~rated to some extent as hereinafter described
to a~ford automatic self-alignment of cross-hatched ~e.~., x-, y-
) ele~*rodes to define an array of cross-cvers, automat~cally
slaved in cor~ect array positions. Dcts of light are prcduceable
at the cross-overs to yield controlled Ip;x~lsl as sm211 as a
single dot or with a grcup of dcts ~a few or many) defining each
P~.
In acccn~ance with the inventicn ~Plected areas of the
tantalum cxide (preferr~bly adjacent stripes in a SQt, wi~h an
array of repeatlng such sets o~ ~tripe8) æ e o~ different
thicknesses to produce di~erent color responses to
wo go/16057 2 ~ 5 913 ~ PCT/US90/03335
~ ?;,~
., . ~"
-5-
incident/transmitted light. AscGrding to a further ~ of the
invention ~he tantalum oxide "layer" h~s internal sublay~rs of
tantalum oxide and a tr~nsp~rent material, e.g., silicon dioxide.
Ihere can be multiples of such sublaye~s stacked over each other
to enhance the brilliance of color response, according to a
further asp2ct of the invention.
The color contr~l elements ar~ ~preferrably) side by
~lde in a sin~le thin ~ilm layer or in each of several such
~ublayers therQby a~Pording high intensity. The general
illuminating light passin~ thrzugh color bands of the cantrol
layer projects aver a wide angle space after passi~g through the
color layer with ~nl~c*r~pic cptical resFonse, i.e. aver 90'
(pre~errably aver 135') o~ vie ~ angle. ~he tantalum oxide
~ilm, or the like, is vary stable and resistant to savQre
conditions o~ t~mp~ratur~ an~or acidia ar alkalin~ anvironme~.
It ~ ~ormed by ancdic oxidation u~ing an und~rlayer o~
t~n3prrcnt khln ~lm net~ coa~in~ o~ ~ha m~t~ a~ ~n
ia el~ctrod~. rrh~ m4~al may b~ 1
layQr of e~ectrically eonduative, tran~parent material ~or
~ptimum resistivity ~n end use.
Where th0 anodic oxide separates x-, y- electrodes or
the like ~a~ indiea~ed above for prcferred crhxxluDents~ then a
very high dieleetric eonstant separati~n of such electrcde groups
c2Ln be formed with high ele~t,ieal insulating value, but
acoommcdating close spac ~ .
Other objects, features, a~d advan~ages will be apFarent
frcm the follcwlng deta;~ed descriptic~ of preferred embodlments
taken in c~njunction with the acccrç~vry m g drawing in which:
, ~ . ,,... : ., .:.. .. . . ........ .. . . . . . . ..
, : , " .,. : : . . . . .. : . , .
WO 90/160~7 2 ~ 5 ~ ~ 3 ~ Pcr/US90/03335
--6--
E~ I~IaN OF q~ nRa~
~ IG. 1 is an i~ic sketc~h of an ~r~i~t of
a di~play .syst~n of the inven~
~ I:GS. 2 and 3 are lateral ar~l transverse cmss-section
sh3tches (tak~ ak the re~ective viewing dlrections II-II and
III~I~ o~ EIG. 1) ~N ~n expand~d scale, o:~ a portion of the ~IG.
1 ~bod~nt;
~ IGS. 3A, 3C ar~ 3D are secticned sketctles, further
expanded and hiqhly schematic illustratLng stepe of construction
of a portion o~ th~ oolor control ~ection (and a part of the
pixel s41ection s2cticn) o~ the FIG. 1 embodim:nt and FIG. 3B i9
a flow ch2rt outlln~ o~ those cc*~truction steps ~nnka that there
i~ a chang~ ln ccnstrLction ~n FIGg. 3A--3D compnrod to FIG. 3
wh~ra~n th3 ~para~ oleotxodc~ o~ FIG. 3 ar~ o~itt~d and
r~placed by y- ~lectr~de~ in~egrn~4d wi~h color ~trip~s in FIGS.
3A, 3D)~
FIG. 4 is an expanded ~ace vi~w o~ the glass substrate
(screen) o~ the FIG. 1 embodiment indicating 0electi~ely
established doks of light passage an~ blockage an~ a si~gle pixel
arbitrarily established as a nine dot by nine dot square
(althcugh a pixel could be established m~ch larger or as small as
a single dot):
FIGS. 5 - 7 are sim~lar face ~iews for other embodime*ts
of pix~l c~*l~mdnation on the di~rlay screen;
FIGS. aA an~ 8~ are dia ~ s of usage o~ the color
fil~er of the display ~ystem withcut hi~h resolution areas
segrega~ion, bNt rather as a broad area color control ~ilter ln
';' ` ~ ! ' , ~ , . . .
W V 9Q/~6057 2 a ~ 9 l 3 ~ PCT/US9~/0333s
.~ .
--7 - ~
~ssi~e (8A) and reflective (8b) m~des;
FIG. g is a sectioned sketch (taXen laterally as in FIG.
2) of a variation of the FIGS. 1-8~ entxxLu~ents using kuss bars
to reduce resistivity losses alon~ the elongated conductors; and
FIG. 10 is a related cir~uit diagram.
FIG. 11 is a trace of decreasing sheat resistivity of an
indium~tin-cxlde coakiny as enhanced thrcugh an aspect of the
present invention.
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WO go/16057 ~ ~ 5 ~ ~ 3 P~/US90/03335
a ~.
-8- :~
rEIaIlED DESC~I}TICN OF E513~3~RED ENE01TN~N75
Referr1ng now to FI~. 1, there is shown an embcdlment d
the invention comprising a light source 10; a light passage
section 20; and a display screen 30 with a color de~i ~ back
coating 40 (at the interface-planar region between 20 and 30)
hereinafter described. As variants frcm this embod~mcnt, (a) the
light ~cuxce can be s~t back at a distance or (b) the light
souxc~ and llght ~ilt~r can be in~egrated in vario~ ways as
explained bel~w. The viewer's position is indica~ed at E. m e
elements 10, 20, 30 are pr~ferrably of compact ~lab-like form and
can each be made in thicknescPc mubet~ntlally below an inch.
FIG. 1 al~co ahcws that the section 20, which is electrically
controlled has x-electrodes 22 and y-electrode~ 24 in the ~o~ms
o~ arrays o~ linear conduc~o~s in spaced paxall~l planes (one
plane for each array~. ~hen electrlcal curr~nt is supplied to
ons x-el~c~r~d~ c~nduc~or a2 and ono y~el~c~xodc connection 2~,
~he ~ o~ ~iv~ ~m i5 controll~ (~g into
aacount voltage drops along the lengths o~ such elongated
conducto~s) so that a voltage iB supplied to an essen~ially
tubular cro~ cve~ ~pct.
The light sourcc 10 pre~errably comprises a ~ull
specbrum, level intensity source, but in specialized applications
(or for economy) may be of narrow spec*ral range (wlthin or : :
outside the visible range) or with unusual intensity or
attenuation at particular wavelengths. Ihe light scurce material
chDices can be electrolu= m escent, ~nc~u~#R~ent, fluorescent, or
- other thermal, phckovoltaic or dlsK~nge m2ans.
FIGS. 2 - 3 show the light pass element 20 expanded side
and top view sections of the FIG. 1 ar~ul~3n~nt comprising wi~es
(or striped coatings or other eguivalents) 22 and 24 ~or x- and
~- electrodÆs, re2pec~1vely. ~h~ ele~trcde wirQs o~ skrip~s ar~
,, " : ,, , , :, , . ::,,: , : j :,. - , .. .
w o go/160~7 2 0 5 ~ 1 3 ~ PCT/US90~03335
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g
of fLne diam~r or span and ~andwich a phokovoltaic liquid
~stal mat~rial 26. When crossing x- and y- electrodes are
active a~ a crossover material spanning point, the local material
is activated to pass or block light (depending on the selected
material) to produce a high resolution spot of light passaga (or
blockage) of no higher than .005" x .005" or as lcw as .0001
inches x .0001 mches, preferrably about .0005 to .001 inches
(.0125 to .025 mm: l/2 to 1 mil) x .0005 to .001 inches, or
circular equivzlents. Generzlly, for uni~orm spacing of x- and
y~ electrode arrays the sp~t will be in-between ideal circular
and squar~ configuration (an approximate square wlth rcunded
corners). But essentially per~ect squares or circles of light
passage (or bloc~age) can be pro~uced with specialize~d elec-
trode/light-con~rol-material combinations, or elongated spots can
be E~xxh~3ed, using ~rti~ac~s well kncwn to those ~killed in the
art o~ hlgh resolution displa~s, ~; ;
FlGS~ 2 ~ 3 and 3A ~l~a ahow ~h~ gl~s~ di~play ~reen 30
and ~k~ oolor de~ining back coating 40 a~or~ln~ ~ protec~ed,
high re501ution color de~inln~ ~ys~m. Ihe screen can be made o~
varicus ~orm~ o~ glass or glass equivalents suited to various
aE~llcations, including tra~p~rent or translucen~ plastla and
c~ramic plate ~or mRsh) materlals. Ih~ coating 40 can comprlse
(e.g., as in the ~IG. 2 - 3 embcdiment) a base 42 o~ tantalum and
an overlayer 44 of anodic lly formed tantalum pentoxide, in turn
overlaid with a protective coat 46 of silicon dioxide. The
coating 40 preferrably ccmprises (e.g., as in the FIG. 2 - 3
&mh~;mP~t takÆn together with FIGS. 3A--3D) a tranrp rc~t bass
portion 25 of, preferrably, about 3,000 Angstroms thick
indium/t m oxide which ' ccntrollably coated on the screen 30
(or onto a tempor~ry substrate and then transferred to the
screen). Ihe coatlng method is pref~rrably sputtar~ng (under
pref d conditlons o~ 1 X 10-5 Torr F~ re (with a partial
E4~isure oP ~iK microns o~ oxygen ~n a bac ~ d ~nert
:~:' - ' ' ':! , " . . , '` : . . ~ . . . ' ~ .'.'`. . . . . .
WO 90/16057 2 ~ t~ ~ 1 3 a PCT/US90/0333~ ~
--10-- .
ambient gas), one t ~ volts, 1.5 anps discharge, spu~kermg
an indium/tm ~ e ca ~ target with deposition conditions
adjusted to give akout five ohms per square sheet resistivity
indium/tin oxide. Such indium/tin Gxide systems per se are well
Xnown and characterized in the display arts. They are
transparont in the full visible spectrum and have oon~ul}able
electrical resistivlty/conductivity further conditions. The
lndium/tin oxide is overcoated with a thin layer 42 o~ tantalum
nitride, pre~errably on the order o~ 1,000 Angstroms and applied
by vacuum deFcsition, sputtering or electrolytic molecular beam
epitaxy (M~E). ~he tantalum nitride ls then anodically oxidized
to form a layer 46 of tantalum pentoxide at a thicXness effective
as a blue filter. Interval stripes 26I are etched in the coating
~0 dcwn to the glass level. Ih~ remain~ng isolatRd metal/metal
oxide stripes ~6G and 46R are th0n ~ ized to di~ering oxide
thickne~ses o~ adJacent such skripc~, ~n a x~p~at~n~ s~ries o~
~t~ o~ grad~d tantalum oxide thickne~s ~ yleld~ng di~xent
color re~pon9q~ aorre~pon~ng to ~an~al~ oxida ~hiaknc~e
~ndicated ~9 cxi~ atripes 4~, 46G ~nd 46~ (typically wi~h
combined tan~alum and tantalum cxide thicknesse~ d about 1,600,
1,400 and 1,200 Asgst~rms ~ ti~ely, based on an original
1,000 Ar~strom tan~alum ~ilm, to de~ins red, green and blue
responsiva stripe~, r ~ ively). Ihe isolated strips 42/25 are
available as ancdic e~ectrcde conductors to form stripes 46G and
46R to green and red. By "response" or "respo.nsive" to a giv~n
color we mean that the stripe will pass that oolor spectral
cc=ç=Dsnt of a light source. qhe three adjacent stripes 4~R, 46G,
46B de~ine a set 46S whlch ' one o~ a series of many such se~s
spanning the ccating ~o define a full display area.
It will be ncked that in the FI~. 2 - 3 s~bcdim~nt
separate y-electrcdes 24 (preferrably o~ optically tr~c~oun3nt,
but electrically conductive ma~qr~al such a~ indium~tin oxide,
I.q'.O.) ~or light passage elem2n~ 20 and ~an~al~lm str~pes ~6 are
.` :: , . : ,:,. :.:: ., ,: . , , ": ,., .. ,.. ;. :.:: ,., ~ .", :, "
WO 90/16057 2 ~ PCr/~ gO/03335
F~
provided (as anodic electrodes and, ultLmately, as color
filters). Ih2re is a problem o~ aligning electrodes 2~ and 26
which can be overoome. It can also be avoided. As shown in FIG.
3A, I.T.O. stripes 25 (or a ~ull base layex before etching in the
stripe intervals 26I) can be provided under the tantalum layer(s)
42 to enhance oonductivity thereo~ ~or service as y-electrodes of
element 20 ~hareby resolving alignment problems,
Th~ ~nodlzing (oxidation) conditions ccmprise a series
of anodi~ing steps at dif~er~nt voltages applie~ to the sheet of
indium/tin oxide overlaid with tantalum (acting as an anode) and
a distant ccurtcr-electrode (cathode) to produce the respec*ive
stripes, under anodization oonditions and oontrols, a~ ~ll as
criteria, well kncwn in the electrnchc=ical art~, inoluding
pre~errably, ~or present purpo6e~ ~ use o~ citric acid a~u~cu~
electrol~ta. Cbnventlonal high resolution n~ ng t~chniqu~ m~
~tcp. ~kX~ , ik i5 p~e~arr~d ~ when in~ n~l ~tr~pes break up
the indium~tin oxld~ ~tripQ~ - to u~a the in~ium/tin oxlde base
layers a~ select~vely activat0d electrodes tor simultanecusly
acti~ated a~ diP~erent voltaga levels) to ~acilitate anodization.
qhe pre~erred normal process, as indlcated in FIG. 3B
(for ccrstsuc*ion o~ an i~ted y-electr2de color control
stripe array), is to coa~ the glass with I.T.O.: then coat with
Ta2N: then anodize to blue transmit: then to etch interval
stripes (using conventional photo lithographic processing
including a mE~k~ng step to create precise, reliable alignment
and width cont m l of intervals and rl=eLsLing raised strires);
~hen anodizing g ~ trar ~ it arxl red trar ~ it s~ripes: then
dÆpositing pbokoresist protection mask over the ~hree colors,
leaving in~erval stripes between color i~tripes clear: and then
deFositing cpaque material over ~he entire plate. Finall~, on~
li~ts o~ unwanted cpa~u~ ma~r~al and r~L~L~ng phLtor~sidue.
" " ~ . ; . " ' ' ' ' ' ', ' ' ' ' ~ ~ , . , ' ' . ', . .
wO 90~16057 ~ ~ 5 ~ ~ 3 ~. PCT/US9o/0333~
m us the adjacent stripes of a resultant set are
separated by high resolutian cpaque interval segments. Alterna-
tively, high resolution interval defining mask stripes can be
applied to the coatm g a~ any other stage of development. Such
intervals, when used, provide the cpportunity for sharper relief
(contrast) to colors.
FIGS. 3 and 3A prcvide expandRd ~llustration o~ the
above described s~riping usin~ intervals between color stripes of
an RGB set and between sets. Ihe glass screen 30 is of twenty-
~ive to forty m~l thickness depcnling on total size of display
for rigidity and coated with repeating sets, each comprising
three stripes 46R (red), 46G ~green), 46B (blue), ~ep æated by
intexvals 46I. The latt~r may be bar~ or bac~illed with an
opaque ma~erial. The interval~ pres~rve el~ctrical saparation o~
stripes ~6R, ~6B, 26G ~3 well a~ ual di~tinctn~ o~ ~uch
oolor ~tripe~ n3tcd ab~va, the ~tripe~ ar~ ~hln ~ilnL~ wlth
mwltipla l~y~r~ ~he wldth ~pan o~ ~ch o~ stripe~ 26R, 26G, 26B
i5 abaut .005", p~ rrably a~g., .OOlll ~or use at p~ ~ t
~ndustrial goal l~vel~ in the ocnsumer TV field prac*ice (being
.0l5"); but, ~or okher applications, e.g. H~TV, the width can be
set as low as .OOOl"-.0002"). This is rela~able ~o selected
spot sizes of the light filt~r section ~0 and desired display
screen color resolution andVor desired pixæl size, as a ~hole,
for the end use display, all as dlsI1~;scd further, below. Ihe
stripe width is preferrably uniform, but may be non-uniform for
scme applications. ~he interval stripes are from twenty to one
hL~x~n3d fifty Feroent of adjacent color stripe widths (taking an
av~rage where adjaoe nt stripes are of different widths). of
ccurse, the ~ s~ripe can be made sm2ller or omitted (i.e~,
unber ten peroent o~ adjacent active stripe width).
~ IG. 3A alsD shows th~ associated light source lO pr~du-
.,. . :. . , , . :. . .
: ~ ~: . ,: : . . : , "
W O 90/16057 PCT/US90/03335
~ 2 ~ 3 ~ ~
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cing a un1form, preferrably collimated light output Ll and
electrically controlled filter section 20 (typically abou~ ten to
forty ~ils, i.e., .010-.040 in. range) prc~ucing selectively
Fx~3d large or small spots of li~ht I2. As note~ above, the
reverse stra~egy can be us0d, i.e. selective blocXage. Large
spots of light passage ~or blockage) are ccmposites o~ adjacent
3mall spcts of such passage ~or blockage).
Ag m~ntioned abov~, FIGS. 3A ~and FIGS. 3C-3D) also
show a further emkodlment o~ the invention wherein light source
and control are combined as shown at lO/20-EL using an
electrolum1nsccnt material ~or other artifact, e.g., an array of
semiconductive light emitting diodes or light emitting
Fhw~phor~ he ~lectrode strips 22, 25 prcvide the cross~ng x-,
y activi~ation matrix ~or ~lective li~ht emission.
Pra~r~bly, a ~ on oxidc lay~r ~nct ahown) o~ abou~
1,000 ~ngstrom~ o~ th~ckn~ d~po~ d ~v~x tha ~ant~l~m oxide
strlp~s by ~putter~ng or chamlaul vapor deposltion, for
pr~tection witlh minimal llght attenua~ion. Se~uential layers of
Ta205 e~nd g10~ i.e" ~veral ~Ise~s~ each typically two or three
ma~ b~ udded to enhanc~ or "peak" th~ tre~nsmission percentage e~nd
provide brighter response. This is shown, as applied to stripes
26B, 26G in ~IG. 3D with tantalum repeats 42-l, 42-3, 43-3 and
t ~ um oxide repeats 44-l, 44-2, 44-3.
~ IG. 4 is a fa oe illustraticn of stripes of adjacent
color sets overlaying the high resolution filter defin3d e~s x-,
y- array of activatable ligh~ passage (or blockage) spots. Ihe
x- an~ y- electrales (22, 24 in PIG. 1 or æ, 25 in PIG. 3A) of
light fitter 20 enable uniform cor~trolled ~ts 20L o~ selectable
liS~ht passage or blockage. These can be of essentially cim~
~c~m of, sa3,r, .0001 inc~h d~er wit~h mini~ overlap, if any,
o~ adjac~t ~pcrts. I~e stripea 26B/ 26G, 2~ o~ a ~e~ 26S can be
..: .. ... ... . . . . . .. .. .. . ... ..
.. . . . . . ~ . ; . . , -
w o so/l60s7 PCT/US90~03335
~ 0 ~
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of .0002 inch width with i ~ stripes 26I, batween stripes of
a set and between adjacent sets, o~ .0001 inch width, to produce
a ~ ~ le set color span wid~h of .0009 mch. For purpcses of
FI~. 4, the use of ~ s 20L aligned with cpaque intexval stripes
26I is assumed; these are, of oourse, superfluous ~nd can be
omitted in high volume ~ tion designs (or at least electrical
controls for such cross-over locations can be omitted or set at a
de~ault llght blocking mode as shcwn in FIG. 4).
Ihe x-, y- electrodes can be controlled with a pixel
st~ategy d uniform size pixels d width d one or more dots
(crosscvers) or sets of doks and ;height o~ one or more dots or
sets of dogs in integral ~r non-integral units. Each such pixel
as arbltrarily de~ined ha~ a selectablllty o~ s ~ and
intenslty cholce~, ~hr~ugh s~lectl~e passage or blo~kags o~ ligh~
in ~ele ~ l am ~ ~r ~ o~ s ao~iva ~ l) ~ rough colar
Ihe usual t~rm 'p~l', as a Pund2men¢al uni~ o~ display
resolution is an arbitrlry ccnitru~t a~ applied to the present
inv~ntion (thcu3h correspondlng to a phy8ical 3pO~ in a raster
~can cath~de ra~ tube, llght emitting diode matxix, discharge
tube matrix, inca~descent lamp ma~rix or like state-of-~he-art
displays). ~ccrpting the ccnventional te~m pixel arbitrarily, as
applied to FIG. 4 and defining a piXf~ width PW as cne set width
and pixEl hQight EH as a height equal to that wiæ h, then a
.0009" x .0009" pixel is establishsd (i.e., abcut one ~;1 x cne
~il). This may be compared with the so called high d0finltion
television ~ d pixel, which - in mLst currently commer~ial
or proposed-as-oommercial e=b~rimlr¢m has a pixel o~ eight to ten
mils x ei~ht to ten mils wi ~ i~ht dimensions; NT~C ~U.S.)
co~venti~nal television (in bome s8ks) of abcut thirty mil9 X
thirty mils; or pr~ecklQn ~elevislon systems o~ 9ixty to eighty
W O 90/16057 2 ~ 3 ~ PCT/US90/03335
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use fifteen mil x fifteen mil pixel standard and stabe of the art
LLD oomputer monitors use a twenty-five mil x twen~y-five mil
pixel. hven if thP~ FIG. 4 e=bcdlment is derated by a factor of
five times (i.e., to a five mil by five mil 'pLxel'), it still
exceeds state of the art resolution. Mor~over, the distinct
pixæl limitation can be avoided in the present invention, with a
computer controlled x-, y- electrode control affording
intRrleaved pi~Els (or to put lt another way referring to the
spoks 20L as th~ ~bnd~r*al ~ ts Or resolution).
Staying with th~ exampl~ of a FIG. 4 as deEined above
and assuming each sF3t 20L to be normally light tDac=p rent when
not activated and ~paque (as shown by shading-in in the ~igure)
when activa~ed by a voltage appli~d ~rom it3 c~nssing x-, y-
electrcde~ (the blocking strategy), then it is se~n hcw colox is
constructed r~or the 'pixel' o~ PW/P~ width ~nd h~igh~ (.0009" x
.0009", or nlna ~ x nir~ ~ts, 20~ as p~v~o~ql~ d~:~in~l).
}latctlir~ ac~a~ n ~G. 4 ~a~ ~ntroll0d
bloedcir)g:
~ o~ all ~t3 aligned witlh the ver~ical interval
stripes, as a ~le~t to, or in lie~ of, cpaque materials of
~he stripes per se, f~r ~xntrastJ
-- some of the red vertical stripe's s~s;
-- none of the green vertical stripe's spots; and
-- all Oæ ~he blue vertical stripe's spots.
~he net effect is a predominantly green pixel of maximum
intensity with a contributed red compcn~nt Oæ abcut forty percent
n2uc~mlm intensity which a human viewer ~or machina imaging viewer
o~ human resolution and percæptian capacity, mor~ or lQss)
W O 90/16057 2 0 ~ 9 1 ~ ~ PC~/US90/03335
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detects only as a compo~ite color. This together with dozens, or
hundrEds of adjacent oontrolled pixels prcvides the viewer color
impression. It will be appreciated that apart from intensity
control, there is a high redundancy of color selection signals
impo6ed on a single 'pixel' to assure reliable response even in
the ~vent of partial control system failure.
FIGS. 5 ~ 6 show c~hex variant~ o~ pixel control (in
~ace view a~ in PIG. 4, but with d~ts indicated as rectangles).
Both e=bod1ments have a one spot plxel. In FIG. 6 interval
striping 46I is shcwn. In FIG. 5 thR array of y- electrodes
(ur~nooat oomponent 25 of stripes ~6 in FIGS. 3A - 3D) and~or X-
electrodes (2 V FIGS. 1 - 3D) may have to be thinned dcwn to avoid
sh~rting o~ ad~acent such electrodes, e.g., a .0035~ condNctive
elect~ode wld~h in relat~on to a .005" color s~ripe.
Xn F~GS~ 5 and 6 red, grE~n and blu~ altQrnat~ in 1~
relation ~n the s~xipc~ ~R, ~G, ~6~. ~ut it will b~ understood
that other ratlos can be prov~ded. For example, human
observation favors repeating multiples of ~:2:6 of
blu2:green"red, respec*lvely, ~or optimum control. Ihis kind of
balanced xatlo can also be used to compensat~ for variances in
phosphor tor LCD) or lamp s ~ range or guality in the light
passage/blocka~e/origination sec*icns of the display system.
FIG. 7 shcws a ~ such e=tx~L~nent with a -horizontal
stripe width 22 equal to the a ~ te of five vertical electrode
stripes 25 and associated intervals 25I (all buried m a single
oolor stripe layer 46B/blue). Astivation of a cross-over pair
(one x- electrode, cne y el ~ e~ wfill light up (or block
light) in ten doks, if the ccnductive strips 25 are ganged or
~ . Alternatively separate electrode connections can be
m3de to 25-l, 25-2, etc. for mcra precis~ ccn~rol.
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F~GS. 8 and 8B show usage of the oolor control section
withcut strip m g or other areal configuration, used 6imply as a
f;lter in transmission t8A) and re~lective ~8B) ~odes.
FIG. 9 shows (in transverse section, as in FIG. 2) a
display s~stem whÆre ths y- elec~rodes 25 ~e~, s.g., FIG. 3A)
are prov.id~ wi~h ku~s-~ars, e.g. B(Y), at interval~ to establish
low resistance path lengths to all regions o~ the y- electrodes
and in turn ~o each dok d~ined by a cr~s~ ove~ of such a y-
electrode wi~h an x- electrode 22. Similar ~Lr~tegy can be
p m vided for electrodes 22. qhe r ~ tan~ equivalent circuit is
shown in FIG. 10 ~ e sec~ions o~ anodic oxide coat m 3s 44
together with crossing-ovcr x-, y- el ~ e portion~ 22, ~5 act
~ an a~ray o~ capacltor~. m e lnsulativ~ value o~ tha anodic
oxide i~ ~upplemantRd by that o~ the pho5phor clectx~luminescan~ !
layer.
min indium/tin oxida lay~r~ c~n ba u ed ~or
t ~ ~ ne~ ~ut u~ing tha kLss bar~ to l~mit voltage drcps
along electrode length~.
Tha ~ontrol o~ spct ~lection and pre5entation o~ a
screen display can (advantagecusly) be simLlkanecusly lmplemented
over a whole screen (or large section of a screen) - in contrast
to a raster scan or like roll m g implementation` of display
control. 2ut roll m g implementation can be adm~JI~b~o~d in the
present case ~or some aesthetic reasons and/or to utilize
While color e~ltL~l in terms of primary colors of
additive synthesis have been descr~bed, other repeating color
stripes of additlve or Eub~tr~ctive s,y~thesis systems can be
applied. ~h~ available rang~ o~ colors can be ccrstantl~ varied
~rcm sec*l~n to ~ecti~n o~ a di~pla~.
W O ~0/16057 PCT/US90/~335
2~59:L3.~ ~
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Cuntr~l ~ystems utilizlng the above display formats can
comprise use of one or more o~ the following exemplars,
extrapolations therefrom or equivalents or extensions now
apparent to those skilled in the relevant display art, given
benefit of availabil~ty of the present invention and its
disclosure herein.
qha d1splay sys~em can be made in selecked small or
laLge sizes with uni~rmity o~ performance unlimited by edge or
corner e~fects o~ the types associated with CRr displays or the
like. Resistance over lengths of x-, y- control electrodes can
be a limitation at very long lengths (e.g., several hundrsd light
spots l~ng~h); but thi~ can ba circumv~nted b~ modular
con~truotion o~ th~ ~ilter portion and/or usa o~ (p m ~x~ably
tzansp~rcnt) buss bar~ ov~rlapping tha ~ilt~r el~ctrodo Wi~9 to
carry high~r vol~a~ ncdo~ to tha ~nt~ior o~ t~h~ r ax~a.
Th~ gla~s 30 (or a precu~sor tx~n~r ~uustrata) can ba o~
lndo~ini~a length ~n manu~aabure or m~de in conveni~nt bakch
~izes and cut to end-user sizes c~g needed. lhe basic filter
construction i~ ~imilarly ~laxi~ble as to economical stock
~anu~acture c~nd custom selection o~ usable si~es.
Several variations have been discussed abcve relative to
a oore e~bKdirent. Several further vzriations can be made
~ sistent with the scope an~ spirit of one or re aspects of
the present invention. For example, color control matexials
other thc~n tan~alum ~ ide can be used - e.g., oxides of
other valve metals af~ording an adherent film.
Ihe indium/tin oxide stripes, or equivale~ts, are usable
for the~r optical prcperties and for thair electrical prcFerties
(carrying current to provide a mcnolithic anode electr3de or
distinct ancdes in th~ anodic ~xidati~n step) and n~chanical
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19
~ies as a glass to tar~tal~n substrate }:)ridge, all as slla~
a~ove. But further, in eTxl use, i~i~tin ~ide stripes can be
us~ as electrodes to ccxntrol re~se (and,/or on-off re~onse)
of averlying coating layers.
Ihe basic color stripes ~and inten~al stripes, w~en
used) are sha ~ above as arrays o~ long st~ in a single
direction. Bu~ Gros~ etching, a~er a need for eleY~brical
ccntinuity ha~ passed and using appropriate masking or selective
etching ~an pro*uce lands (isolat0d mesas or islands) of color
responsive oxid~ spoks.
Ihe light souroe spectral range ~nd intensity and4or
glass ~oreen trau~xlrIocy characteri~tics are further distinct
variables co~r~llable in design selection or utilizAtion to
~urth~r impact ~ d~spl~y.
While x-, y~ orthcgon~l coondln~ hcwn ab~ or
~ilter al~ctrode arrangements, one could use various non-
orthogonal coordinata sy~tems, e.g., polar coordinate6. A
varia~y o~ llnsar or non-linear ~ n~s ~e.g., lo~arithmic)
~an ba impc~ed in each coordinate se~.
Ih0 areas of applica~i~n o~ the i ~ ion include - ~ut
a ~ not limited to - consumer and industrial video, computer
mcnitors, ins~rumentlti~n display6, military displays, sports
arens scoreboards and cther variable public billkoards. lhe
Invention is also utilizable as a ~ontrolled light source
independent of d;splay purpcses in sizes ranging from very small
t~ v~ry large, taking advan~age o~ one or m~re o~ the flexibility
of~ control control, resolution, economy o~ nEunufacture andVor
ckher aspects of the present invention.
Ih~ inv ~ on al~o ocmprises mean~ ~or enhan~ing the
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W O 90/16057 ~ ~ ~ 9 1 3 PCTtVS90/03335
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ocnductivity of the indiumrtin-oxide underlayer or overlayer
material (where used) and resultant enhanced indiumrtin-oxide
prcduct (a coating) and enhanced coated pro*uct. Ihis aspect of
the invention can be applied to materials for electrical
conductivity compatibly with high light transmission.
h this last-mentioned aspect of the invention,
~heet reslstivity on tha order of belcw 2.0 (in s~me instances,
below 1. O) Ohms~p~r~guare i5 achi~vable ~cmpared to five to
~ifty ohms-per-square in the state of the art. Ihe impact of
thLs is to enable longer linear runs andVor reduc~d thickness of
conductive strLpes of indium-tin-oxLde (or the like).
The realization of reduced electrical
re~istivity/higher alectrlcal c~nductivity is achieved with only
a modest lo~s o~ optical tran~mis~ivity typically less than
twQnty p~rcent at m~st ~p~ctral rang~ o~ int~xe~t in ~lect~ow
cptic d~splay or ~iltQr application, ~uch a~ tho~n ~l~ed abcve.
Realizaticn o~ SU~l improvement is preferrably made
thxcugh th~ follcwing prcces~ ~t~ps:
~ 1.1) Establish a base layer free of external i~ns
li.e. alkali ions as applied to a glass substrate), preferrable
by beginning with a glass such as sode lime or Corning 7059.
ClPar the substrate with detergent an~Vor solvents and dry it at
150 in air or inert gas for about half an hour to remsve
isture and follow up by sFutter~etDh or like radiant energy
~ to removs residual ccnt~=inonts. qhe sputter etching ~c at
Gre-h~lf to one ~ owatt und2r abcut 8 millitorr vacuum and after
prior evacuation and argon backfill.
(1.2) Cover its sur~ace to b~ o~ated with a
(sFL~IY~cposited or chemical-vapor-depositiQn deposi~ oon
W O 90/16057 2 ~ 5 9 ~3 3 ~ PCT/US90/03335
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dioxide layer of about 2,000 Pnqstrc=s thickness to mask the
aIkali ions or okher ex*ernal species from interacting with
=ubsequent coating and provide sukstrate for further coating. A
pre-processed silicon glass substrate free of such surface
species LS another approach to the same end.
(1.3) Then the so-coated glass is heated at 350-
450 C ~or abcNt ~i~te~n minutes under 5 x 10-7 mm ~g. pre~sure.
~ 2) A layer o~ 7000-10,000 2r~stloms of indium~tin-
oxide is sputter deposited an the so-treated substrate.
(2.1) Ihe ~irst 100 to 200 ~ngstroms o~ such
deposition ~eqyivalQnt to the ~irs~ ~w monola~ers the~eo~) is
ocrduoted undRr bia5 ~ ring cQndit~ns to maxlmiæe pur.i~y and
density. ~ha 0pUt~sr~n~ o~ th~ indiumrkln-oxide i~ ccnduated ~n
atmc~Fhe~s init~ally ~vacua~cd to 5~10-7 mm. ~g., then back-
L~ w~ a~o~3 w~ nl p~ ~n
4 to 5x10~5 mm ~g
~ 2.2~ Withcuk ~emcval from the sputter system, the
~putt~ring d~scha~ge is ~hen termin~ted and a vacuum bake of 400-
500 C ~or abcut 15 ~ s at 4 to 5x10-7 mm. Hg. is applied to
create oxygen vacancies.
., .
FIG. ll shows the develcFment of enhanced (reduoed)
shRet resistivity of tWD sa~ples of (l.l) soda lime and (1.2)
Corning 7059 coated with indio=-tln--xldb as described above.
l~e y-axis (l~thmic) i cit~ are arxl ~e x~
(lir~3ar) ~s time in minut~ of the final bakir~ step of (2.2) to . :~:
create a~en vacancies. Ihe ~heet resistivit~ of the san~les :
begins at s~ cllms per s~are and d~ dramatically to well
with no ~urth~r change aft~r abo~t an haur and a bal~.
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Bulk resistivity o~ the coating is also reduced to
about 0.5x10-4 chm-cm, a ~=bstantial impruvement over commonly
available indiumrtin-oxide ma~erials.
lhe processing as described above can be implemented
over a broad area or through masking to provide mLltiple stripes
o~ conductive coating (alternat.tvely interval stripes can be
~tched or mach~n0d cut o~ a broad area oo~ting).
Some o~ t~le processing steps dPcrribed abcve can be
supple ~ or supplanted by laser or electron beam etching,
micrc~achining, ion deposition, electroplating, electrcphoresis
and okher processes.
m e enhanced matallic co~ting can be und~r 20,000
Ang~kroms but i~ pro~rab~y w~ll undar 10,000. ~here a
~Ub9~rat0 d1~P1AY~ a.g. ~ Qpkl~al ~ransmi~8icn ~n v~ble ~a~g~
the metallic oo~0~ gl~s~ ~lth low ~heet resi~tiviky o~ the
aoating) will di~play over 80-~, pre~errably 85~ or more
~ransmis8ivlty in the 8am~ 9pec~r21 range, i.e. re~uction of less
than 20~, pre~errably less than 10~ via ~he coat~ng. In contrast
withcut th~ special enhJnce3ent a 10,000 Arystrom cc~ventional
coating of indium-tin-oxide on such glass would typically re*uce
to about 60% ~ ssion and w~uld have higher electrical sheet
resistivity.
.
qhe above de~czibed enb=nccmc~t pr w 2ssing mcdifies
semicund~ctive charar~Qristics of the indium-t m-uxide coating or
the like thrcugh axygen vacancy creation (or equivalent neans) to
yield the lo~ered resistivity with a higher degree of
F4~ rVation o~ ç ical tra0smiYsivity
Filter applica~lons d th~ ~nvantion - in re~lectiv~
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W o 90/16057 2 ~ 5 ~ ~ 3 ~ PCT/US90/03335
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and trans=ds~ive mcdes - are characterizel by abrasian, thermal
and environment rasistance, including super-saturated salt
solutions and/or -55 C to +550 C range consistent with 90%
transmission/reflection, ease and low cost of tailoring to
pæticular applications.
It will now be app~rent to those skilled in the art
~hat oth~r embodlmRnt3, i~prcvements, details, and uses can be
madR consistent wlth the letter and spirit o~ the foregoing
disclosure and within the sccpe o~ this patent, which is limited
anly by the follcwing d aims, ccçscruei in aocordance with the
patent law, including the doctrine of eguiv21ents.
Wh~t i~ claimed i~:
:
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