Chapter 1 - Introduction
CARROLL TOUCH
1-2
Modular Flat Panel Mounting and Environments Guide
Technological Overview
The operation of all scanning infrared (IR) touch systems is based on
the creation of a grid of IR light beams above the viewing surface of a
CRT monitor or flat panel display and the recognition of the location at
which individual beams within the grid are interrupted. To create such
a grid, IR light emitting diodes (LEDs) are paired with phototransistors,
each set constituting an opto-pair or physical beam, to create a
horizontal (x-axis) and a vertical (y-axis) array of beams. The two
arrays of beams and their circuitry make up an opto-matrix frame, as
shown in Figure 1-1.
Figure 1-1. Scanning Infrared Technology
As shown in Figure 1-2, a Carroll Touch modular touch frame designed
to function with a flat panel is composed of an opto-matrix frame, an
IR-transparent protective bezel, and a transparent filter. To complete
the touch system, the modular touch frame is linked to a modular touch
controller via the modular digital interface (MDI), which is a standard
8-pin telephone-type plug attached to the touch frame by an 8-pin cable.
Touch Activation
Inside and Outside Edges of
Infrared-Transparent Bezel
Grid of Infrared Light
Opto-Matrix Frame
Inside Bezel
Edge of Active
Display Area
