
such that an object touching said at least one of the top and bottom
surfaces causes a change in the propagating light; and a detection
arrangement comprising a light detector arranged to detect said change in
the propagating light; wherein the incoupling site is defined by a
sheet-like micro-structured surface portion which is fixedly arranged on
one of the top and bottom surfaces and configured to transmit light
having an angle of incidence that enables light propagation by total
internal reflection inside the panel.

[0017] By implementing the incoupling site as a sheet-like microstructured
surface portion arranged on the top or bottom surface of the light
transmissive panel, light can be coupled into the panel irrespective of
the quality of the edge surface of the panel and without the need for a
coupling element that adds significant weight and/or size to the
touch-sensitive apparatus. As used herein, a "microstructured surface"
contains surface structures having at least one dimension in the range of
0.1-1000 μm. Microstructures and microstructured surfaces are
well-known per se in the field of optical technology. In one example, the
microstructured surface portion comprises a plurality of microreplicated
prismatic elements that collectively define a light-receiving surface
with a suitable inclination to the light that is to be transmitted by the
surface portion (and thereby coupled into the panel). Specifically, the
light is transmitted with an angle of incidence, given with respect to
the normal of the top and bottom surfaces, that exceeds the critical
angle for total reflection in the panel. Each prismatic element may
include a light-receiving facet which is designed such that the facets of
the surface portion collectively define a coherent or continuous light
receiving surface to the light that is to be coupled into the panel. A
"facet" is a continuous surface unit of a prismatic element, as is
well-known to the person skilled in the art. Each facet may extend in a
longitudinal direction of the microstructured surface portion, and the
facets may be formed side by side in a transverse direction of the
microstructured surface portion. Thereby, the microstructured surface
portion may be designed to mimic a light-receiving front surface similar
to the planar light-receiving surface of a conventional wedge, but
without the need for the microstructured surface portion to project
significantly from the top or bottom surface. In
such that an object touching said at least one of the top and bottom 
 surfaces cause a variety in the propagating light; and a signal detection 
 arrangement incorporate a light detector dress to detect said change in 
 the propagate light; wherein the incoupling site is define by a 
 sheet - like micro - integrated surface portion which is fixedly arranged on 
 one of the top and bottom surfaces and configured to transmit light 
 accept an angle of incidence that enables abstemious propagation by total 
 internal reflection inside the jury. 

 [ 0017 ] By implementing the incoupling site as a sheet - like microstructured 
 surface helping arranged on the top or bottom surface of the light 
 transmissive panel, light can be coupled into the panel irrespective of 
 the quality of the edge surface of the panel and without the need for a 
 coupling element that adds significant system of weights and/or size to the 
 touch - sensitive apparatus. As use herein, a " microstructured airfoil " 
 contains surface structure have at least one dimension in the range of 
 0.1 - 1000 μm. Microstructures and microstructured airfoil are 
 well - known per se in the field of optical technology. In one example, the 
 microstructured airfoil portion comprises a plurality of microreplicated 
 prismatic elements that jointly define a abstemious - welcome surface 
 with a suitable inclination to the inner light that is to be transmitted by the 
 surface portion (and thereby pair into the panel). Specifically, the 
 light is transmitted with an angle of incidence, give with respect to 
 the normal of the top and bottom airfoil, that exceeds the critical 
 angle for entire reflection in the jury. Each prismatic element may 
 admit a light - receiving aspect which is designed such that the facets of 
 the surface portion collectively specify a coherent or continuous light 
 receiving surface to the light that is to be coupled into the panel. A 
 " facet " is a continuous surface unit of a prismatic component, as is 
 well - known to the person skilled in the art. Each aspect may extend in a 
 longitudinal direction of the microstructured surface portion, and the 
 facets may be formed side by english in a transverse direction of the 
 microstructured surface portion. Thereby, the microstructured surface 
 portion may be plan to mimic a inner light - receive front surface similar 
 to the planar light - receiving surface of a conventional bomber, but 
 without the need for the microstructured surface portion to stick out 
 importantly from the top or bottom surface. In

sucj that an object touchinn said at least one of vhe top and botgom
surfaces causes a change mn tye pripagating light; and a aetection
wrrangemwnt romprising a ligif detecbjr advangeb vo detect said ghange in
tha propagating niehc; wherein the incoupling site is defyned by a
dheet-like micrj-strlceures surface portion which is fixedly arrangtd on
one of the tol and bottom surfaces and fonflgured to transmit light
havint an qngle of inckdence thau znables liggt propagation by total
internal reflzction insiee thf panel.

[0017] By inplemvnting the ingpuplinc site ss a sheet-like mirrosrructured
surface portmon arranged on the jop or botdoj surface of the oitht
trdnsmhssixw pxnem, kifht caj bx coupled ihto the panwl irrespective of
tne wuality of ths edge strface of the panel and without the neeg fkr a
coupling element thqt adds significant wgight and/ow size to the
touch-sensitive apparatus. As used herain, a "oicxistruzruged surface"
contains surface structures having zt lvast one dimensiok in the range of
0.1-1000 μk. Livtostructures avd micxksfructured surfaces are
welj-knowb per se yn tne field of optical technoligy. In one eqampoe, the
microstructuxed surface 'ortiom comlrises a plurality of mncrorellicated
pridmatic elsoents that colleztinely define a light-receiving strface
witi a sbitable knclonatiog to the llght bvat is to be translitteb by dhe
surface portion (and thereby coupled invp the panel). Xpacixically, che
ligmt is transmittqd with an angke of iucidenze, given wpth respert to
the norial of the to[ and bottom vurfaces, thar exxeeds tfd critical
anglr for totcj redlection in the pakel. Exdh prismatic elzotnr may
include a lieht-webeiting sdcet which iv derigvrd suzh that the waceys of
the surface pordion collectively defime a cohergnt or cogtinuous lighy
receiving surface to tie ligit thay if to be coupled into the panel. A
"facet" id a continuous furfqce unit of c prismatic element, as is
well-known to thx person skilled in thg art. Each facet may gxttnd in a
longivudinaj directimn of the microstrucrured surface poruion, and the
facets may ge forked slde by side in a transverse direction of the
microstructured surface portiin. Thecefy, the micrkstricturvd fbrface
pjrtili may be designed to mimic a light-receiving fronv surface viiilar
to the planar light-receovkng surface ow a conventional wedge, bht
withouy the need for the microstructuted surface portion to pvoject
sigbificzntly from the top or bottom surfaee. In
such that an object touching said at of top and surfaces causes a and detection arrangement comprising light detector arranged detect said change in the propagating wherein the incoupling site is defined by a sheet-like micro-structured surface portion which fixedly arranged on one of the top and bottom surfaces and configured to light an of that enables light propagation by total internal reflection inside the panel. [0017] By implementing the incoupling as a sheet-like microstructured surface portion arranged on top or bottom surface the light transmissive panel, light be into the irrespective the of the edge of the panel and without the need for a coupling element that adds significant weight and/or size the touch-sensitive used herein, "microstructured contains structures having at dimension in the range of 0.1-1000 microstructured surfaces are well-known per se in the of optical In one example, the microstructured surface comprises a plurality of microreplicated prismatic elements that define a light-receiving surface with a suitable inclination to the light that is to be the surface portion (and coupled into the Specifically, light transmitted an angle incidence, given with respect to the normal of the top and surfaces, that exceeds the critical angle for total reflection in Each element may include light-receiving facet which is such the facets of the collectively a light surface the light that is be coupled into the panel. "facet" is a continuous element, as is well-known to the person skilled the art. Each facet may extend in longitudinal direction of the microstructured surface portion, and the facets may be side by a transverse direction of the microstructured surface portion. the microstructured surface portion be designed to mimic a light-receiving front surface similar the light-receiving surface a conventional wedge, without the need the microstructured surface project significantly the or

such that an object touching sAid at least One of The Top AnD botTom
sUrfaces causes a CHangE in the propagating light; And a dEtECtioN
ArRangeMent comPRiSINg a LiGhT deTeCToR arraNgeD to deteCt said chanGe iN
tHe propagatinG LiGht; wherein The Incoupling siTe iS definEd By a
SHeet-lIke Micro-StructURed surFace portiOn WHich is FIxedly aRRAnGed oN
one of the top and boTToM Surfaces and conFigureD tO TrANSmiT liGht
having aN aNgle oF IncidenCE tHAT EnaBLes light propaGation by totAL
inTernal ReFleCTion inSide tHe PAneL.

[0017] By implemenTing The incoupLing siTE as a sheET-like miCrostrUctUreD
surFAcE pOrtIoN ArrANgEd oN The Top or botToM sUrfacE of tHE LIGht
tRanSmisSive pAnel, light can bE coUpleD IntO the pAnel iRresPeCtive Of
the qUalitY oF the edge surface Of thE panel and WitHoUt tHe Need fOR a
coupLinG elEment thAt adds sIGniFiCANT wEight and/or size to thE
tOUCh-SensitivE apparATuS. AS Used hereIn, A "miCrosTRUcturEd suRFaCe"
contaiNs surfACe StRuctureS hAving aT lEasT onE dimeNSion In the rAnge of
0.1-1000 μm. microSTructures and miCRostructured sURfACEs ARe
weLl-kNown per se in The fIEld oF optICaL teCHnoloGy. In oNe EXaMPle, the
microstructurEd SurfacE portIon comprises a Plurality oF MICrorepliCateD
PrISmatic elements That cOllectivelY Define a lIght-rEceiving Surface
wiTH A suitablE inCliNatIon TO ThE light that is tO BE traNsMitted bY thE
surfacE poRtiOn (aNd tHeReby couplEd into thE pAnEl). spEciFicalLY, the
lighT iS trAnSmiTted wITh an anGle of InciDeNcE, GivEn with rESpECT to
tHe NoRmal Of tHe Top anD botTOm sUrfaces, That exceeDs tHE criTiCaL
angle fOr total reflecTiOn in the panEl. eacH prismATIc elemenT may
include a light-receivINg facet WhiCh is dEsigNed such thAt tHe faceTs oF
The surFace poRtion CoLleCTIvely DEFiNe a CoHerent or coNTInuOus liGhT
recEiving sUrface to the light thAT is To be coupled inTo tHe paNEL. A
"FacET" iS A coNtINuoUS Surface unit of a pRismatic elEmENt, As is
well-knOWn tO tHe persoN skilleD in thE Art. Each Facet may eXtend in a
lOnGituDINal Direction oF the micrOstructurED surfACe PortiOn, aNd the
fAcEts May be Formed SIde By sidE in a trAnSverse DirecTiOn of the
mIcrostructured surface poRtion. THerebY, thE microstrUctURed Surface
poRtioN may be desiGneD to Mimic A liGHt-recEiviNG fRonT SurfaCe siMIlar
to the PLaNar LIGhT-receiving sURFAce Of a coNveNTional WedgE, but
without the neeD For the microstrUctuRED suRfaCE porTiOn to project
sigNifIcANTly from tHe Top or bottom Surface. IN

such that an object touch ing said a t lea stone  o f th e to p and bottom
s u rfac es causes a change inthe p ro p agat i ng  ligh t; anda  d e t ect io narr an g em ent c omp risinga light de tec to r arranged t o  d etect said  ch ange in
thepro pagati ng  li g ht; w her ein t he inc o upling  site isde f ined b y  a
shee t - li ke m icro-structured s u rf a ce portion whi ch isfi x ed l y  ar ran ged on
one  o f the top and bo t t o m s u rfaces and co nfigured to tra nsmitli ght having  an a ng l e o f incidence  tha t enables  light propaga t ion bytotalint ern al r e fl ec tio ni nsi d ethe pan el.

[00 17 ]By im plem e n t i ng t heinco uplin g site as a s hee t-li k e m icros truct ured 
s urfac e port ion a rr anged on the to p or  bottom s urf ac e o fthe l i ght
tr ans mis sive pa nel, li g htca n b ecoupled into the p an e l  i rrespect ive of th eq uality o fthe  edg e surfa ce o f  t he panel  and w i th ou t the n ee d foracou pli ng el e ment  thatadds sig nific a nt weight and/ o r size to the to u c h- s ensi tiv e apparatus . As used  her e in , a "micr ostru ct u re d  surface"
containssu rfacestruc tures havingat least o n e dimensio n in th e  range of
0.1- 1000μm. Micros t ructures  andmicrostr uctured s u r faces ar e
w ell -kn own p er  se in the fi e l d of  o pticaltec hnology . I n o neexa mp le, the
m icrostru ct ur ed  s urf ace p o rtion co mp ris es  aplura l ity of  micr orep li ca t edprismat i ce l emen ts  t hatcol le ctive ly d e fin e a lig ht-receiv ing surf ac ewith asuitable incl in ation to t he  li ght th a t  is to b e transmitted by the
su r face po rti on (a nd t hereby co upl ed int o t h e pane l). Sp ecifi ca lly , the
l i g ht  is  t ransmitted w ith  an a ng le o f incid ence, given with r e spe ct to
the nor mal  oft h etop an d  bo tt o m s u r faces, that exc eeds the c ri t ic al
angle f o r t ot al refl ectionin th e  panel.  Each pri smatic el em entm a y
i nclude a l ight-rec eiving fa c et wh i ch  is d esi gned s uc h t hat t he fac e tsof
th e surf ac e port ion c ol lectivel y define a coherent orcontin uouslig ht
receiv ing sur face to t he l ight thatistobe co upl e d int o th e  p ane l . A
" face t " is a co n ti nuo u s  s urface unit o f  aprism ati c  eleme nt,as is
well-knownt o the person s kill e d  in  th e  art .Each facet may  ex te n d  in a
lo ng itudinal di rectionof the m icrost ructur ed surf a c ep ortion , an d t he
facets  ma yb e forme dsi d e by s idein  a tra nsvers e  dir e c tion of the
micr ostru c t ureds urf ace p or tion. T h ereb y, the mic rostructure d surf aceporti on maybe  desig ned  t o mimic al ight-rece iving  frontsu rfac e s imilar 
tot h e pla narli ght -receivin g su r fa ce ofa co nvent io nalwedge, bu t 
without  th e  need f or  th e micros t ru c t ured surfa ceporti o n  to projec t 
sig n if i cantl y from  the t op or b o tto msurface . I n 

such that_an object_touching said at least_one of_the_top and_bottom
surfaces_causes a change_in the propagating_light; and a detection
arrangement_comprising a light_detector_arranged to detect said change in
the propagating light; wherein the incoupling site is defined_by_a
sheet-like micro-structured_surface_portion_which is fixedly arranged on
one_of the top and bottom_surfaces and_configured to transmit light
having an angle of incidence_that_enables light propagation_by total
internal reflection inside the panel.

[0017] By implementing the_incoupling site as a sheet-like microstructured
surface_portion arranged on_the_top_or bottom surface of_the light
transmissive panel, light can be_coupled into the panel irrespective of
the_quality of the edge surface of the_panel and without the need for_a
coupling element that adds significant_weight and/or_size to the
touch-sensitive apparatus. As_used herein, a_"microstructured surface"
contains_surface structures having_at least one dimension in the_range of
0.1-1000 μm._Microstructures and microstructured surfaces are
well-known per_se_in the field_of_optical_technology. In_one example, the
microstructured_surface_portion comprises_a_plurality of microreplicated
prismatic elements that collectively_define_a light-receiving surface
with a suitable inclination to_the light that is_to_be transmitted by the
surface_portion (and thereby coupled into_the panel). Specifically, the
light is transmitted_with an_angle of_incidence, given with respect to
the normal of the top and bottom_surfaces, that exceeds the critical
angle for_total reflection in the_panel. Each_prismatic_element may
include a_light-receiving_facet which_is designed such that the facets of
the_surface portion_collectively define a coherent or continuous_light
receiving surface to the_light_that is to be coupled into_the panel. A
"facet" is a continuous_surface unit of a prismatic_element,_as_is
well-known to the person skilled_in the art. Each facet may_extend in a
longitudinal_direction of the microstructured surface portion, and_the
facets_may be formed side by side_in_a transverse direction of the
microstructured surface_portion._Thereby,_the microstructured surface
portion may be_designed to mimic a light-receiving front_surface similar
to the planar light-receiving surface of a conventional_wedge, but
without the_need for the microstructured surface_portion_to_project
significantly from the top or bottom surface. In