An apparatus and method for an inexpensive, simple to make, self-aligning
molded waveguide made of an optically transparent material and that can
be used to generate a grid or lamina of light for use with touch screen
displays. The molded waveguide substrate includes a plurality of lenses
and a plurality of waveguide grooves corresponding to the plurality of
integral lenses respectively. After the substrate is molded, the grooves
are filled with an optically transparent material to optically couple and
align the plurality of lenses and the plurality of grooves respectively.
In one application, the molded waveguide substrate is positioned adjacent
a touch screen device. A light transmitter and an imaging device are
optically coupled to the molded waveguide substrate, and a processing
device is coupled to the imaging device. The processing device is
configured to determine a data entry to the touch screen by deciphering
the coordinates of an interrupt in the light created in the free space
adjacent the touch screen device when a data entry is being made to the
touch screen device.