Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
wo 93/19450 i~ l 3 2 !~ S 6 PCI/AIJ93/0011~ ;
IDENTI~ICATIQN PLATE AND ~IETHOD OF MANUFACTI~E
This inventiorl relates to a visible identification pla~e for a
vehicle or other mobile apparatus for which identifica~on by visual
and/or elec~onic means i5 desirable. Ln one particular aspect the
inven~orl may be more ge:nerally considered in rela~don to a ~umber
plate for a vehicle.
The ~vention also ~e~ate~ to a method of protu~g an
iden~fic~tion plate ha~ring visual andlor e~ecko~c identification
~eans, as disclo~ed hereinafter.
Identification plate~ are &dv2nta~eously highly visible both
dur~ng the day and at night, easily read both d~g the day and a~
~ught, and, economical l:o manufacture.
It is also advantageous if an identifi~ation plate can be
easily and economi~ally man:ufactured to irlcorporate a passive ~hip
of the ~pe which will electronically "feed~bac~" information
contained on the c~hip,~ which may be specific to that iden~fica~don
~late, when the plate i~ ~n the pro~nity of electronic means enabling
:~ informa~on on the:chip to be read.
One ~:of ~e more advantageous aspects of visual
iden~ifica~on plates at: night 'dme, par'dcular~y but not exclusively,
those used as:nu:niber~plates c~n vehic~es, occurs when ~e whole
: ~ ~ identifica~on plate is re~ective to impingin~ light (hereinafter
referred to as nre~o-refle~iYe") rat:her than only the readable
information ther~on being:retro-reflective.
~ When~ a retro-reflectiYe material is p~si'doned on a re~o-
reflec~ive background of;~the sa~e or different degree of reko-
~eflec~, a~problem wi~ halation arises. This problem is greatest
when th~ ion to: be~ read Oll the phte is the more highly
retro-re1ective p~r~on of the plate. When light is re1ected from
:su:ch an infor~ation ~plate:; the becomes di~cult or
~possibk to rèad bec~u~e of a ~halon ~ffe~t w~ich is createtl around
the edges of ~e ~ ore ~reflective information, tending to blur the
i~ge a~ ~erge the light re~ected IErom ~e plate 2nto a diffuse
~: image. 1~ may be cau~ed by the more highly re~e~ve nature ~f
part of ~he plate, ov~powering th~ less ~e~ective por'don, ~r~ by a
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Wo 93/19450 pcr/AlJ93/ool 1~
~1~2956
tendency of the reflected light to be more diffuse by nature. The
applicant does not wish to be bound by either of these possible
theories, however.
In the case of a vehicle number plate it means that the more
5retro-reflective por~on, that is, the numbers or letters which make up
the information part of the plate, can be difficult or impo~sible to
read at night, if the entire plate is made reflec~ive. Yet, a substan~al
degree of retro-reflectivity is highly desirable from a safety point of
: ~ view, at night, in relal~on to number plates of motor vehi~es.
10It is an object of the pre~ent ~nYention to provide a visual
iden'dfication plate which is substantially completely retro-reflective,
in which the infonnation desired to be visually read hag a different
retro-reflectivity from the remainder of the identification plate, and
in whi~h the halation effect w}~ch occurs wi~ a combination of retro-
15reflective surfaces is substantia}ly reduced.
It is also an object of the in~en'don to provide an
economical method of manufa~g such a vi~ual identifica~don
:
plate, in which a passne c~ip, such as~ a surface acous'dc device, may
be included. Such ~a device will be referred to as a ~tagn
20~ ~ For the purposes of this specificahon a i'tag" is defined as
an electron~c unit which includes a ur~e encoded number and/or
additional information, ~and, means which allows the mlmber and/or
; the o~er informalion to be read remotel~r by electronie s~nning
: means at a:reading:~point. ~
one ::aspect of the invention there is pro~ided an
entifica~on plate, ~ luding;~ a retro~eflec~:ve material folming the
substan~ ority~of the surhoe; o~ ~e plate; said su~face havLng
a first and a second main~reg~ons o~:differing re*~ectivity, sa~d
re~ions together; constihlffng ~e substanffal majoraty of s~ud surface;
aid f;rst re~being:more retr:o~ ve than:wd seco~d region,
~: ~and being ~:~eparated~ ere~om by~a~non-retro-re~ective b~rderpo~ n; vthereby t~ re~uce~è~hala1don effec~ ~f said first region
sufficien~ly tD allow it to be visual~y~read: when lî~ht i6 reflected from
aîd surface.: ~
3S In~ one aspe~t o~ ~ invention: ~e a~ least one ba~ground
WV 93/19450 ;~ i 6 P~/AU93tOo11~
region is less retro-reflective than the information re~ons.
In another aspect of this embodiment of the inven~on the
border portion is of substantially uniform thicl;ness.
In another aspect the invention provides a method of
producing an identification plate comprising; masking a sheet of
re~o-reflecti~e ~terial; ~tting said mask to define a plurality of
informa~ion regions; further cut~g ~aid mask around the ot~ e
5~d plurality of ~o~'don ~e~ions whereby to provide a plurality
of border portions adjacerit thereto; whereby the remainder of said
mask c~vers one or more ba~kgr6~ d regions; removing said ma~k
material ~t said border portions; rendering the expo~ed plate in the
area correspo~ding to said borde~ portions non-retro~re~ec~ve;
~ remoYing t~e mask mater~l eoxre~pondin~ to t~e orle or more
baclcgrou~d re~ns; trea~ the expo~ed plate in the area
correspondin~ t: ~aid one or more bacl~grourld regions to reduce ~e
re~o-~eflectivity thereof; and, removing ~he mask material from said
- informa~on regions.
In ~ne em~odiment of the method there is i~cluded ~e
addi~donal step of ~ecuring a tag (a~ here~fter defined) to a norl-
2Q metal~c ba~g plate secured to ~e re~o~eflective material, to
complete the con~uction of the identifica~on pl~e.
In a second embsdim~t of the method of ~e in~ren~on,
the plate is rendered non-re'ao-reflective in the b~der portions b~
appliuition of a light unpermeable coa~g, after removal of the mask
material there~om.
In another embo~ nt of ~his aspect the one or more
backgr~und regions are cs:~ated with a transparent, c~lo~ed material
after removal o the mask, ~rom ~e area corresponding to ~he oxle ~
- 30 more bac~ground regions.
In a~her ~odiment of t~e me~od ~ ~e inven'd~
after IeDlO~ral of t~e mask cDvering ~e ir~o~na~on regions, it may
b~ de~ired, wh~re ~or i~tance an 1nformaJdon area is r~la~ely la$geO
to ~reat t~at~ or a 11 ~e, informa~on area or area~ t~ sligh~r ~educ¢
35 - ~e~r retro reflec~ . HoweYer, ~e ~ctént of redlacti~n would be
.
,
WO ~3/19450 PCr/~U93/OOJ 16
9 5 ~ 4
less than that applied to the backgrs:)und regions of the identification
plate.
In a preferred embodiment of the inven~ion the retro~
reflective materi~ is a high intensity corner-cube material formed of
rigid plas'dcs material.
In a still further embodiment of ~is aspect the mask is
made from a material having an aclhe~ive backing and covers
substantially ~e whole surface of the retro-re~ective material.
:~ order ~at t~e inven~on may be more clea~ly understood
a descrip'don will now be provided o~ a particularly preferred
embo~ent of the inven~on, in relatio~ to a me~od fo~ producin~
a vehi~le number plate and with reference to ~he accompanying
dr~w;ngs. The de~crip'don i3 in no way limi~ng on the inverl~on.
~D~
Fig ~1 shows one: embodiment of a vehicle n1lmber plate ~n
accordance w~th the i~ven~on;
Fig 2 shows a second embodim~nt of vehicle ~umber plate
in wh~ch a passive c}up is to be cons~ucted in ~e n~nber plate;
Fig 3 is a side view of the second embodiment of Fig 2 in
assembled f~orm. ~ :
Refernng to the drawings and: to Pig 1 there is shown a
veh~cle num~r plate~ lO,~ consisJdng of a sheet 11 of rigid re~o-
~: ~ reflec~ve high intensity corner-cub~ pl~ 5 material which has a
hi~h~ degree of retro-reflecti~ity. Sheet ll ~8 of ~he size of a vehic~Le
number plate and is~ pr~vid~d on the front face *ereof wi~ a mask
12, whi~ a sheet of adhesi~e ba~ked; material.
:~ 5heet 11 ~nd ~sk 12 ~ tre~ted by a letter ntlmber punch
machine whi~ provides cut~ 13 (seen on~ the mi~al 1 of Fig. 1)
agh ma~l~ 14 to fir~tly define the i~osma~ regior~ of num~er
: ~ -30 plate 10~ in ~i~ case ~e~letters A, B and t~ n~neral 1, and which
secondly, provideli cuts 15~ ~o ~een on the numeral 1) which define
border pc~tions ~14 :su~round~ng ea~h edge oÇ l~e letters and
: numbers. ~he semain~g;area o~ ~heet 11 i~ a ba~kgEound r~gion 16.
- Such letterhlum6er pun~h~ma~ines are well kna~vn in the ~t an~
: ~ : 35 provide substa~tialiy even border p~r~ons ~4 ~Te~p~ g to the
WO 93/19450 . ~ 9 5 6 PC~/AU93/00116
- 5 -
outline of the letters and numbers used.
Af~er mask 12 is cut in this manner, sheet 11 is treated to
remove border portions 14, expos~ng part of the re~o-reflective sheet
11. The front face of ~heet 11 and mask 12 are then sprayed with a
bla~k coa'dng material 17 (seen on the letter A of Fi~. 1), and dried.
Ba~kgroulr~ region 1~ sf mask 12 is ~en removed and the front face
of s}leet 11 ancl mask 12 are ~en ~prayed with a ~ansparent
coloured coa~g 18 (~hown in part as a shaded area on the left hand
side of Pig 1) which coYers both ba~k~round region 1~ and border
portion 14.
Because coa'dng 18 i~ tr~p~rents background re8ion 16 of
nwnber plate 10 are sJdll xe~o-reflective bu~ to a lesser degree than
an uncoated por~ion.
Finally, the remaining portions of maslc 12, ~ose portions
coxresponding to Sh~ letter~ A, B and the numeral 1, are r~moved.
Because of the pre~ence of non-reflective border portions 14
around each of the information areas, the halation effect desceibed
.
aboYe is substintially diminishet and the informa~orl is readily
visually reada~le at night. Durin~ the day the information is al~o
readily readable, because ~e outlining of the informa'don area~ by
:~ the blaclc border por~ions 14, ~ake regions 12 highly visible and
~learly readable.
While the;applicant:does not wiæh to be li~ited ~o any
par~icular :theor~r, it is believed that the borde~ portions 14 a~ in turo
2 5 ways, firstly d~ring; the day to ~ighlight the informa~oII pro~rided OI~
the number plate, that is the~letters or ~umbers which make up the
~forma~ion ~arried by ~he plate,~ and, at n~ght to reduce the halation
effect as t~e number pla~e re~ect~: i~pin~ing light.
At night, li~ht iDrlpinp-g on the number plate is reflected
:: 30 ms)re by the inforslution :po~tions, ~hat i8 the letters or numbers, and
they st3nd :out ~ore: 6t~1y becæuse of ~heir higher retro-
re~ctiviq. They: are easily readable i~ a ~umber plate co~tFucted
~:n a~c3rdance wi~i ~ inven1ion, *~ ut ~he haL~tiox~ e~ie~ blurring
or di~to~ting the~read~bili~ of ~e number plate a~ a whole.
If it is tesiresl, any~addition~ informatioII may be added to
WO 93/19450 PCI/AU93J0011
9 r~ ~3 - 6 -
number plate 10, by spra~g the information on to the front of sheet
11 with a light-imper~ious coating material. Such information could
relate to the authoAty issuing the number plate, to adver'dsing
material, or, to any other material desired by the relevant authority
to be contained on number plate 10.
~eferring now to ~ 2, there is shown a second
embodim~nt of the inYen~don in whic~ a noII-metallic backing plate
19 is provided on which is positioned a tag 20. 13ac~ng plate 19 i5
brought into conhct with sheet 11, as indicated by the broken lirles,
to ~and~ch ta~ 20 between ~heet 11 and plate 19. Plate 19 is
sec~ared to sheet 11 by any suitable means, and such means in~lude
a~esive.
Tag 20 is forme~ in two parts, a ~urface acoustic wave micro
chip 21 and a ~at antenna portion 22. The reason tag 20 is
sandwiched between l~e ba~k of re~o-reflective sheet 11 and ~he
nvn-metal~ic ba~king plate ~9 is so that, should rlumber pl~te 10 be
~; mounted directly to a me~ fittirlg, tag 20 is spaced ~uf~ciently
therefrom to avoid anterference from that metal fitting when reading
:~ of the in~orma'don on tag 20 by electronic scanning means i~
: 20 performed.
Fig 3 shows assembIed :nu~ber plate lO ~n~is~ng of light
impervious border por'doD~ l~, sheet 119 bac~dng pl~te l9 and tag 20. ~:~
The wavy portion:23 represents the cubed surface of the re~o- :
reflectiYe sheet l1. ~
: If:desired, for ~t;mce, fo~ reasons of protection ~m the
elements or t~ alter~the~overall re~o-reElective charac~er~ of the
-~ number plate, one~or more o*~r tr}ent or translueent coa~ngs
may be sprayed on~the number phte lO, ei~er during the proce~s
~teps ou'dined sbnve~ or befi>re, or after.
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