The default number of bumps is 100 (10 X 10). You need to change these 2A@9jl s
parameters to match your design. Note that LightTools allows many other dwks"5l
placement options, but you will use the Bezier placement option for this O4FW/)gq
example. 5,>1rd<B
5.On both the X Placement tab and Y Placement tab, change the Number of ) F 6#n&2
Bumps parameter to 300, as shown in the following figure. Click Apply after v=?U{{xQ
each change. j.4oYxK!s/
6.Click OK to close the dialog box. SV .\B
Note that the number of bumps is 300 X 300, which results in about 90,000 DG1
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bumps on the surface (~ 5143 bumps/in2). These bumps are arranged in a j[YzBXd
V
manner defined by the Bezier parameterization option. Please see Chapter 5 of pmXx2T#=
the LightTools Core Module User’s Guide for more information. With the ay#cW.,
current parameter values, the Bezier option varies the bump spacing along the F?'=iY<h
length of the light guide. The spacing in the orthogonal direction is constant. "/hM&
The X and Y refer to the local coordinate system of the surface. I,Q"<?&
LightTools Introductory Tutorial * 91 VP=(",`
9}kN9u
HAPTER 5 Introduction to Backlight Design <Fb3\T L
C 4*OL^\%
Examining Surface Properties wJh|$Vn
Using the methods described in previous chapters, you may want to check your HTI1eLZ2
model before you run a simulation. ke|v|@
Click on various parts of the model in the 3D Design View. Or use the System UC^&&
2maI
Navigator to select different surfaces and view their Properties. %JDG aG'
1.In the System Navigator, click to open BottomSurface of the LightGuide, then 1Nx.aji
click Zones, and then click Texture. *w4jE T>
2.Select SphericalElement, and then right-click and select Properties from the S{j|("W"[
shortcut menu. The Shape tab shows you a graphical representation of the *Id$%O
spherical bump shape that is the bottom of the light guide. 2}]6~i
You might be curious as to why you cannot see the 3D texture property zones you WZ5[tZf
defined. They are invisible by default, because drawing thousands of texture k|-`d
elements can make displaying and exploring the model somewhat slow. If you 6cSMKbgZJ
choose to make them visible, 3D textures are displayed in wireframe, even if the |x["fWK
display mode is set to translucent. Wireframe rendering displays a bit faster and @~fg[)7M
shows more of the technical details. ?GU/Rf!H#
92 * LightTools Introductory Tutorial #(h~l> r
Mm-FdP
m
HAPTER 5 Introduction to Backlight Design 8rXq-V_u
C gBHev1^y
1.Rotate and zoom the model to that you can see something like the illustration )7=B]{B_
below: g~.,-V}
. g^8dDY[%
2.To reveal the Property Zones: ,Ihuo5>/z
a.Right-click in the Design View and select View Preferences to display this Pca~V>Hd
dialog box. pOD|
b.On the Visibility tab, click the Property Zone check box to turn it on. SqFya
c.Click OK. GmtMA|
You will see the wire frame rendering of the spherical bumps on the :ORCsl6-
bottom surface, and a solid color above it. The solid color is the 3D texture 7CUu:6%
of the BEFs (brightness-enhancing films) built automatically by the utility.