Note: Descriptions are shown in the official language in which they were submitted.
2185841
--1--
I l~uuu~; FLvW INR J15T-TYrE G3~NER~
PURPOSE SURFACE C^ATI~G APPLIC~Tt)R
T-~hn~ el~
~he pre3ent invention relatel3 to
nt-1n~7.,~ ink jet p~inter8 and, more pa~ticuli3rly,
~o a 8urace coating ~r~ tor for pri?ltins vlth
suc~ p~in~ers
pi-. L- -C -l Art
In ~ t;n~ u ink j~l: printi~g,
electrically ~ Au~-t~e ~ s ~rr] ~ under
~JL~_ ~U~: to a r-n;fnl~ region tha~ t~ -r--n the
ink to a rl-l~ality of o~ifi--~, typically dLLe~ d
3n a linear array~s). Thc inL ai~;~L~ !~ ~ from the
o~ifices in fi~ which brei~k into droplet
,-?tream~. Inai~ridual drc,plet 6treams ~ electively
~harged ~o 6~h~2r;~nti;~ ly two levels is~ the region of
the brea~c of~ ~rc,m the fil. ~ and charged drop-
i~r ~Afl-Act~Ald from th~ir normal rrajectories
Either the ~fle-r~ drop8 or the llr~ fl~r~ drop9
a~c caught and recir~-ulatcd, and the o~her drops are
allo~ed to proceed to a print medium~
In ~ome situatios~, it is ~ e to
pro~idc a ~,,L,~ e with a ~ur~ace coating ha~ing a
very unlo2~n surace dcn=ity This te~-hn;q~e can
~150 b~ ul3ed to make ;nt~nt;tn:~lly non-uniform
aur~ace coatingE; or those vith int~i ~Rt~ de~igng
The ~rior art ig rcplet~ h p~v~ ~cs ~or
}Jro~ g s~face coatings. Ui~o? L~.ately, existins
~LV~ ULCli for producing surface ~ fin~5 invol~re a
contact technique, wherein a fine povder or emul~:ion
18 3pread onto a surface, or a spraying ~ ~cc,~u~
~3ing droplecs i~ applicd having a ' t random
di3tribution of volumes and i~pact ~rajectorles.
Contact s3ur~acc coa~ing p,~ c, are typically
~ 2 1 8584 1
--2--
sloY, _ t:J. with the speed of current in}c jet
printing systems, and the ~spro.l.~ bility of soroe
t-~rhniq~ ~ill depend on the distribution of
parti~ls ~ es used. It i3 also di~icult to
s diqtribute the particles ~enly ov~r broad ~u~ race~
~nd ov~r lo~g ~imes. Coatings with appreciablc
det~il are dif:Eicult eo make or ~odify and involve
using ~ 7ar~F, or some ot~er hardware control,
which mUqt }~e changea ~hen a new pattern is to be
p~vl~c~d,
In an effor~ to overcome the problems
A~ rii~ te~ w~th contact qur~ace coating 1~ v a~,
~on ~ L~,-vL ~ have ~een de~reloped
- L~ tely, ~ILost non-con~act pLv~ 3~q involve
Jo~e form or a spraying p~ ULe:, and only have
li~ited conrrol oYer ~ irri~liry, Such ~vcerl~s
all;o require i~ m~ , such as 8 ~ Ate, ~:o produce
~ ?ta;~ surface coAt;ns-~ A spraying t~rhni~e is
algo A~f~c1~.lt to manage in ~it~ti~nq wher~ the
dropl~Cs touch after being applied to the ~uL .L~c.te
and r~ oqcF~ into larger dropg before drying.
It ig par~lr~ rl~ A~ ir~Ahle in the
ph~ e-~tjc`~l industry to he able ~o provide a
su~b~rate covering, such iP~i a - 'j r:lt~3 pad or
biandage, where- th~ ~ ''r,p~nn il~ unifo~nly,
controlli~bly applied to the skin surface.
It is Pesn thsn ehat ~here exi~it~ a need
for an i ~ 3urface coatil~g arrl; rpi r~r proce~
which v _ ~~ the problems ~3o~ te~ with th~
3 o prior E~rt
Summa n~ o~ the In~r~nt; rn
~hi~ need iq ~et by ti}~e ~r, n~; nlln~ Elow
ink ~et general purpoSe ~urface coat~ng applica~or
3~ proce~s ~rcr~r~in~ ~o ~he pre~ent invention, wherein
~ 2~ 8584 1
a fast, non-contact coating method p~ovides quasi-
imiform surface den6ity coa~ing ~rith excellenr
i hi 1 7 ty .
I~ acc~,~ dl~ L with one aspect of the
pres~nt inven~:ion, a method i9 urjad to apply a
coating s~Z~st~tnce to an ink j~t printer substrate.
Th~3 method ~ c~c the step~ of dissolving the
eoating ~ L~znce in a carrier f luid to create a
co~ting product, and applying a ~nt~l l, hle pattern
o~ di~crete droplets Or the coating product onto the
~ub:trate This ~, -,.luc~ a uni~orm, control~ble
sur~ace coating on ~he ink jet printer substrate,
The surface coating is tyE ically a liquid ~ol~
~e coating product is ~-~r~ by the ~ nk j et
printer as uniform, co~trolla~le, discrete droplet~,
onto the ~uL~ ~te, and the carrier ~luid i~i allow~d
to ~:V~LCLt~:, leavlng the coating substance on the
.uL3LL~te .
p^-~A~ir~7y, it i8 an object of the
presen~: in~rention to pro~ide a ~uasi-uni~orr,7 surface
de~sif:y coating over bro~d areas. It i~i a ~urther
obj~ o~ t~c present invention to provide such a
coat~ng having ~ nr ~ hil; ty over long
period of t:i~e. It ls yet another object o~ the
pre8ent invention to provide -r,r~ r pattern
versatility,
O~her objects and ad(J~t~- - o~ tbe
inw~ntion vill be apparent from the ~ollo~ing
de~cript ~ on, the ~ , ying drawings and the
~l'r~ claim~.
Brie~ D~8c~iption of thr~( DraWi ~g~
Fig. 1 is one; ~ r~ri-~n of a coating
pattern ~ nqc~ in acl,~,L/l-r~.e with the presen~
invention; and
21 8584 t
Fig. 2 is a flow chart diagram ~t;7i 1 ing
the ~3teps for applyiAg the coating product, in
ac~v, ~..e with the pre~ent invention
Der~7i led De~cri~tio7t of the P~ _f~rr~d ~ ' '; -
The co~ting method a~cording to the
present invention i~ particularly for u6e on a
~7~i7~1~n~7 ir~c jet printi lg system o~ the tyF7e
7-.~herein droF7la:s of ~ nt7;771y i~7 nri~ s77 size ald
v~7l7~nte are pL~J,I~ at high r~y~ A ar.td can ~7e
individually s~ r~-d to ei7~her print on a substrate
or ~e cc~ UL~d ar~td irr~rrolly recirculated.
I7~t ~ .e ~ th the prese7 tt
~r.tv~ntion, the gl~h~t;777~e ro ~e r7epn~it~r7 a5 a
r7 coating if~ dis~olved in a ~nl77tior~ of ink, alconol,
water, or any fluid tnat i3 . ,. ih~ with r7~e
fluid sy~tem 7.7.7~tterials. For p~oper op~7ti~7n of the
pr~t head, as i~ typical, the sti l:~t.jnn op~Pti
point IttU3t ~e ~e t~hl i s:hr d fo~ this f luid and the
~e~istivity ~ tormi~ , If needed, the co7apo3ition
o~ the fluid ~ty ~e changed to iLt~rease the
r~nn~l7~`rivity in or~3er to provide fo~ 'deT''te
drople~t char,g~ ng and ~o7~ 7~ ~l th~tl~h ~to 7~te~ 1-
defined upE7er limit exists for the fluid
resisti~ity, an a~ r~ed value is apprn~ri~ ly ~7oOo
o~n-cm~
O~te coatiAg patterLt, i~lt7~'rat-~d in F$g
1, is ~7J~tain~ y s~nding the proper e~, -~ of
print pul~eg r~o rrint~ 7. 10 aAd maviAg the
~u~3t~Stte 12 a~ ~ t~tlforr7 veloaity past the
printhead, in ~he r7;r~crlr~n o arro~ 14. ~3 will 72e
o~7vious to those Js,cilled in thc art, th~ proper
print pul~es iB a f7~T.tction o~ *7u7~7stra~e
speed, dro721et 3ize, a~td ~ rat j nn f ~ f
cour~7e, rnn~f~ntrSt7-tnn of the sol7lt inn will al~o
2t8584t
affect ~he ~ of prisl~ pulses
r~ntinllin~ ith Fig 1, in ;7r~or~7An--e-
h rhe present i~vention, the coating ~,ccd~ i9
to pu~ dis~reCe ~roplets o~ a coating product 16
onto the ~ub3trate 12. h. ~oaring sllb3tan~e, 37lch 2g
a ~ '7 r~ t it~n to ~7e ahQr~r~r~ into the skin, i~3
diQslolved in a carrier iluid, ~uch as water or
alcohol ~o cre~te the coating produc~ 16 A
controllable pattern of discrete ~7~oplet~ of the
coating product 16 i9 eYr~ d onto th~ ~iu7c7strate 12
}~y the printhead lO. ~ h-t-At~ may ~7e ony
~-7;t lhle su~7strare~ ~uch as a bandage. The carrier
d may the~ ~7e e~r7r~ts~1 o~ the ~u~strate,
leaving only depo-~itc 18 Oc the coating g~ Anr e
15 ~S7~n~ bet~een l:h~ r are ~l~r.. bly la~g~
enough 7 o p~event droplet ~o 7le~~in~ beiore the
coating aries~, ald~or the ~arrier fluid e~ 1/ Q.
i~e~rring nov to Pig_ 2, ;~ c~ntin-7i
~ith Pig. 1, droplet~ 16 are printed such that ono
droplet does t contact any other droplet a~ter
a~riving at the s7lbstrate 12 . i.L_~efo, ~, when the
droplecs 16 dry, indi~idual ~ro~; t,q 18 of ral;idue
r~s~ain On the sl~bstrate 12 7nif ;AI1Y~ then, a
coating ~ QtS~n~e and a carrier ~3 uid are provided,
a~ indi~ated by blocks 20 ar~ 22 o~ ~ig. 2. Thes
coat~ng 5~lh-lrAn~ or example a sterold ~
1~ mixed as a true s~l"r;~ ~ wi~h a carri~r fluid,
fo~ e~cample ~n a~cohol such a~i ~thanol, as indicated
by block 24 The re~ultan~ coating produ~t i8 then
printed on the ~ub8t~ate, a~ in~; At~ ~y block 26
When the alcohol evaporates ~rom ehe printed
droplct, ~t block Z8, then th~ steroid re~Lins on
~he S~_L.c~.~e as individual dor~; tA of
c~y8~allite8, aa in~rA~e~q a~ blo~k 30, to ~e
~5 ~ I .t ~ into the _kin ~hen the cubstrace is applied
-6- 21~5847
~o skin
rt~nq~ nrly, aft~3r printing the
dropletG 16 onto the substrate, the carrier fluid
will evaporate, leaving be~ind deposits 18 of the
S coating rn~ s will be obvicus to those
skilled in the art, the rate o~ evaporation will
depend on the carrier f luid used and the ambie~t and
D~lLDLL~e corldi~ions. Also relevant, of course, is
the degree to ~rhich the solution i~ Ahq~-h~-~i into
the substrate If a highly ~ substrate
material is cho~ien, then the proceYs of the presenC
i~vention may be u~eful ~s a v~ry controllable and
er6J-tile surfa~e i, ~ to~. Conver ely, if the
LD~La~e does not absorb the solution, then the
~Ddividual aro~let~ ~ill ~3vapor~te ~rirh ~ery similar
drying times, leaYing behind small cryst ~11 i t~oq of
the coating r~t~
Sin~e the droplets all have nearly
~ntir ~1 volume3 and the droplets on the ~.~L~LL Ite
are not in contact with each other, ~hen using an
illk jet printi~ Yyste~n of the type r-n~f~ct~--e~ by
Sci~x Digital Printing, Inc, of ~ayton, Ohio, v~ry
uniform cryYt:-l7;n~ growth can be r-inrAin~ f2-om
droplet-to-droplet. In thiq way, powders o~ unifor~n
ZS p~r~icle 5ize may be p--r~ 3 after removing the
material from the su}~strate. After the individual
droplets ~rrive at the ~lib~LLdtC and ~he carrier
~luid .~ L' tC13, the crystallites that are le~t
}:~hind tend to ~e ~ery uniform in size Not only is
the coating applied through a fast, non-contact
proce~s, ~ut the actual crystallites o~ coating
material ~at remain on the su~ rnt~ were ver~
uniform in ~i2e. In a.~ l4~ce ~ith the present
inven~ion, therefore, a substance with a typically
large variation in par~icle size can ~e created wi~h
2 1 8584 1
--7--
a very uniform pzrticle~ size The deposit8, or
coating, tbe~, is ~laked off the cr~;~talli~es.
Therefore, the end product i8 not a coa~ing, but is
a,~otber powder, vith Yery con~rolled and uniform
par~i~le gi~e. If a single layer of the coa~ing
~ater~ al doe~ not provide the required aYerage
~;urfAce den3ity, anDther layer may be applied after
the previous layer has dried i~ence, the coa~ing
Icethod ~ccording to the presen~ invention can be
u~;~d to apply thick, as well a~ thin, coatings~
In~llol rial APPlicability and
~r~y~r~t~ c
The present invention is use~ul in the
field of ink jet printing, and has the advantage of
allow~ng i~or a quasi-uniform surface den~ity coating
over broad are~as ~i~h F-Yr~ nt ~_~L~ . ihil i ty over
lor~g time period6. The coating ~v-,c ~ of the
pre:~ent invention is particularly ussful when
applied to a priating system wherein d~oplot~ of
eqF-nrially i~rt;~l si2e and Yolume are },~v-l~c~d
a~ high f.Lc~ h.,ie~ and can be individually celected
to ei~hor print on a substrate or be captures and
i nt~ y recirculated, It is an sdvantage of the
pr~sent lnYention tha~ atin5c~ can be produced at a
th~yl~ , of up to 120 inches/~rond It i8 a
~urther adYantage oi~ tbe presen~ inven~ion that the
~ni ~rm; ~y Of the coating can be tnade very
reproducibly and at virtually any value of Cur~ace
density Finally, it i~ an advantage o~ the pre3ent
inYention that the versatility o~ ~he sy~tem is ~uch
~hat a varie~y o~ coating pattern can be produced in
any numbe~ or order of ~he desired pattern-
~ving described the invention in de~a~ l
and by re~erence ~o the preferred ~
218584
. ~
--8--
ther~o~, ir ~rill be apparent that other
~odi~i~ations and varia~ions are possible without
departing from ~he scope o~ the in~r~n~iOn de~ined in
the ~ '3~ claim~.
